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IJHCS Tables of Contents: 616263646566676869707172

International Journal of Human-Computer Studies 71

Editors:Enrico Motta; Susan Wiedenbeck
Publisher:Elsevier Science Publishers
Standard No:ISSN 0020-7373; TA 167 A1 I5
Links:Table of Contents
  1. IJHCS 2013-01 Volume 71 Issue 1
  2. IJHCS 2013-02 Volume 71 Issue 2
  3. IJHCS 2013-03 Volume 71 Issue 3
  4. IJHCS 2013-04 Volume 71 Issue 4
  5. IJHCS 2013-05 Volume 71 Issue 5
  6. IJHCS 2013-06 Volume 71 Issue 6
  7. IJHCS 2013-07 Volume 71 Issue 7/8
  8. IJHCS 2013-09 Volume 71 Issue 9
  9. IJHCS 2013-10 Volume 71 Issue 10
  10. IJHCS 2013-11 Volume 71 Issue 11
  11. IJHCS 2013-12 Volume 71 Issue 12

IJHCS 2013-01 Volume 71 Issue 1

Supporting shared representations in collaborative activities: Introduction to the Special issue BIBFull-Text 1-3
  Jean-François Boujut; Stefania Castellani; Frédéric Roulland; Jutta Willamowski
Supporting collaborative sense-making in emergency management through geo-visualization BIBAKFull-Text 4-23
  Anna Wu; Gregorio Convertino; Craig Ganoe; John M. Carroll; Xiaolong (Luke) Zhang
In emergency management, collaborative decision-making usually involves collaborative sense-making of diverse information by a group of experts from different knowledge domains, and needs better tools to analyze role-specific information, share and synthesize relevant information, and remain aware of the activities of others. This paper presents our research on the design of a collaborative sense-making system to support team work. We propose a multi-view, role-based design to help team members analyze geo-spatial information, share and integrate critical information, and monitor individual activities. Our design uses coordinated maps and activity visualization to aid decision-making as well as group activity awareness. The paper discusses design rationale, iterative design of visualization tools, prototype implementation, and system evaluation. Our work can potentially improve and extend collaborative tasks in emergency management.
Keywords: Computer-supported cooperative work; Geo-collaboration; Visualization; Collaborative sense-making; Web-based application
Leveraging underspecification in knowledge artifacts to foster collaborative activities in professional communities BIBAKFull-Text 24-45
  Federico Cabitza; Gianluca Colombo; Carla Simone
Collaborative problem solving often involves actors with heterogeneous competences or that see a common problem from different perspectives: this can make mutual understanding difficult. The paper presents case studies in different domains where collaboration leverages shared representations, and discusses the main reasons why these representations succeeded in fostering mutual understanding. We observed how the technologies proposed to manage those representations were successful only to the extent they were made able to adapt to the dynamic and open conventions that actors adopted during their activities. The point of the paper is that locality, openness and underspecification are key factors in this process, for their capability to promote tacit knowledge and to let competent actors reach a sufficient level of mutual understanding towards some common goal. The paper proposes a conceptual framework to characterize the notion of knowledge artifact interpreted as a semiotic system where actors can make sense of shared and underspecified representations, and derives from this notion implications for the design of a supportive technology.
Keywords: Underspecification; Knowledge artifact; Clinical pathway; Software integration; Chemical design
A framework for the study of external representations in collaborative design settings BIBAKFull-Text 46-58
  Erica de Vries; Cédric Masclet
The use of modeling, simulation and visualization techniques in scientific and technical domains has led to the co-existence of a large diversity of external representations that, when deployed in collaborative work settings, can be designated by the term "shared representations'. This contribution will focus on dyadic cognitive and triadic semiotic perspectives on the issue of interpretation and construction of shared representations. We propose a typology of external representations as a basis for further study of shared representations. As illustrated by examples from an existing corpus, the framework allows describing co-occurrence and superimpositions of different types, as well as transitions from one type to another. In the final section, we anticipate the exploitation of the framework in the light of the design of collaborative systems.
Keywords: Collaborative design; Typology; Shared representations; Inscriptions; Serious game
Collaborative knowledge building with shared video representations BIBAKFull-Text 59-75
  Ralph Barthel; Shaaron Ainsworth; Mike Sharples
Online video has become established as a fundamental part of the fabric of the web; widely used by people for information sharing, learning and entertainment. We report results from a design study that explored how people interact to create shared multi-path video representations in a social video environment. The participants created multiple versions of a video by providing alternative and interchangeable scenes that formed different paths through the video content. This multi-path video approach was designed to circumvent limitations of traditionally linear video for use as a shared representation in collaborative knowledge building activities. The article describes how people created video resources in collaborative activities in two different settings. We discuss different modes of working that were observed and outline the specific challenges of using the video medium as shared representation. Finally we demonstrate how an analysis of collaborative dimensions of the shared multi-path video representation can be applied to discuss the design space and to raise the discourse about the usefulness of these representations in knowledge building environments.
Keywords: Shared video representations; Knowledge building; Collaborative dimensions of shared representations; Perspective taking; Modes of work
Mutual engagement and collocation with shared representations BIBAKFull-Text 76-90
  Nick Bryan-Kinns
In this paper we explore the use of shared representations to support creative activities, focussing on collaborative music making. We examine the effect that user interface features of shared representations have on mutual engagement and show that providing shared awareness mechanisms increases mutual engagement. In particular, we show through an empirical study of 78 participants that providing cues to identity and shared pointers increases mutual engagement between participants, but together these features can overwhelm users. We also demonstrate that support for free-form annotation and spatial interaction with shared representations mediates interaction and helps participants to manage their collaborative activity effectively. In this paper we develop several measures mutual engagement and demonstrate their use to assess the design of shared representations. A key contribution of this paper is the development of a measure of collocation of participant interaction which indicates mutual engagement. The findings of the study have implications beyond the domain of collaborative music making and we outline some design guidelines for mutually engaging shared representations.
Keywords: Mutual engagement; Collaboration; Music making; Design; Evaluation; Creativity
LASAD: Flexible representations for computer-based collaborative argumentation BIBAKFull-Text 91-109
  Frank Loll; Niels Pinkwart
Teaching argumentation is challenging, and the factors of how to effectively support the acquisition of argumentation skills through technology are not fully explored yet. One of the key reasons for that is the lack of comparability between studies. In this article, we describe LASAD, a collaborative argumentation framework that can be flexibly parameterized. We illustrate the flexibility of the framework with respect to visualization, structural definitions and kind of cooperation. Using this framework, this paper presents an evaluation of the impact of using an argumentation system with different argument representations and with collaborative vs. individual use on the outcomes of scientific argumentation. We investigate which combinations of these factors produces the best results concerning argument production and learning outcomes. The results of this controlled lab study with 36 participants showed that the use of simple representational formats is superior compared to highly structured ones. Even though the latter encouraged the provision of additional non-given material, the former is less error-prone. A hypothesized structural guidance provided by more complex formats could not be confirmed. With respect to collaboration, the results highlight that arguing in groups lead to more cluttered argumentation maps, including a higher amount of duplicate elements. An expected peer-reviewing between group members did not occur. Yet, groups also tended to include more points-of-view in their arguments, leading to more elaborated argument maps.
Keywords: Argumentation; CSCL; Visualization
A situation model to support awareness in collaborative design BIBAKFull-Text 110-129
  Farouk Belkadi; Eric Bonjour; Mauricio Camargo; Nadàge Troussier; Benoit Eynard
The concept of awareness was introduced to underline the importance of shared knowledge and enhance collaborative work. Actors require much knowledge about their work situation and their collaborators' activities in order to complete their own activities successfully. This paper first contributes to a detailed literature review about the concept of awareness. This review helps to identify key awareness-related requirements for the development of collaborative systems. The second contribution is related to the proposal of a generic situation model that is based on the concept of entities, interactions and specific roles. This new conceptual framework intends to favor situation awareness and support shared representations. It concerns both technical and organizational design activities and describes the collaborative situations from multiple views and at different organizational levels (project, team and individual). The proposal's interest and its feasibility for use in the development of collaborative systems are demonstrated by instances related to a case study and by analyzing the potential satisfaction of the identified awareness-related requirements. To sum up, the paper offers a synthesis of key context-related concepts and a generic model for the representation of collaborative situations to increase awareness.
Keywords: Interaction modeling; Computer supported cooperative work; Situation awareness; Collaborative activities; Knowledge and information management

IJHCS 2013-02 Volume 71 Issue 2

25 Years of Knowledge Acquisition BIBAKFull-Text 131-134
  Enrico Motta
This special issue celebrates 25 years of Knowledge Acquisition and centers around a breathtaking essay by Brian Gaines, the founder and former Editor-in-Chief of our journal, who discusses the processes of knowledge acquisition, knowledge representation and knowledge sharing across the millennia, and emphasizes the essential role that these processes have played throughout history, as engines of human evolution. In addition to Gaines' paper, this issue also comprises ten short contributions from a number of other prominent Knowledge Acquisition researchers. These provide a broad range of perspectives on the field and reflect the vivacity and diversity of the research in this area. While the Knowledge Acquisition area is by and large healthy and thriving, the shift in the past decade from intelligent problem solving to data acquisition and management can be seen as somewhat 'reductionist' with respect to the original ambitions of the community. This special issue provides a timely reminder of the ambitious goals of the field, its interdisciplinary ethos, and the sheer fun that the community has had in the past 25 years in pursuing the objective of building intelligent and symbiotic systems. I trust that our readers will be inspired and excited by this set of brilliant essays.
Keywords: Knowledge acquisition; Ontologies; Problem solving methods; Knowledge-based systems; Intelligent systems; Symbiotic systems
Knowledge acquisition: Past, present and future BIBAKFull-Text 135-156
  Brian R. Gaines
As we celebrate the 50th knowledge acquisition conference this year it is appropriate to review progress in knowledge acquisition techniques not only over the quarter century since the conference series began but backwards through the millennia to the beginnings of knowledge capture and forwards through the foreseeable future to speculate on reasonable expectations, appropriate targets and potential surprises in the next quarter century.
   "Time present and time past are both perhaps present in time future, and time future contained in time past. What might have been is an abstraction remaining a perpetual possibility only in world of speculation.' (T.S. Eliot, Four Quartets).
Keywords: Knowledge acquisition; Human evolution; Information technology evolution; Propagation scholarly errors; Information overload; World Wide Web; Semantic web; Technological forecasting
From the knowledge acquisition bottleneck to the knowledge acquisition overflow: A brief French history of knowledge acquisition BIBAKFull-Text 157-165
  Nathalie Aussenac-Gilles; Fabien Gandon
This article is an account of the evolution of the French-speaking research community on knowledge acquisition and knowledge modelling echoing the complex and cross-disciplinary trajectory of the field. In particular, it reports the most significant steps in the parallel evolution of the web and the knowledge acquisition paradigm, which finally converged with the project of a semantic web. As a consequence of the huge amount of available data in the web, a paradigm shift occurred in the domain, from knowledge-intensive problem solving to large-scale data acquisition and management. We also pay a tribute to Rose Dieng, one of the pioneers of this research community.
Keywords: Knowledge modelling; French research; Knowledge-based systems
Information is not knowledge, knowledge is not wisdom, wisdom is not truth BIBAKFull-Text 166-170
  V. Richard Benjamins
In this contribution to the special issue of the International Journal of Human-Computer Studies on Knowledge Acquisition I will give a view on the evolution of concepts related to knowledge during the last 25 years and will briefly look into the future. The concepts include knowledge acquisition, knowledge engineering, knowledge management, knowledge level, knowledge retrieval, knowledge modeling, knowledge protection, knowledge retention, knowledge deletion and knowledge privacy. This contribution is a reflection on the theme Knowledge Acquisition based on my experience from 1987 when I started working in this area.
Keywords: Knowledge Acquisition; Innovation; Knowledge
From knowledge science to symbiosis science BIBAKFull-Text 171-176
  Jeffrey M. Bradshaw
In the mid-1980s, Brian Gaines first developed a model to predict the trajectory of progress in human-computer relationships, including how the knowledge science research programme would naturally transform itself over time into something he called "symbiosis science.' In this article, we reflect both on the extraordinary prescience of this model, and the contributions and challenges faced by researchers intent on progressive achievement toward the aspirations it inspires.
Keywords: Symbiosis science; BRETAM; Autonomous systems; Software agents; Personal assistants; Multi-agent systems; Human-agent-robot teamwork; Sensemaking; Wisdom
A cognitive science perspective on knowledge acquisition BIBAKFull-Text 177-183
  Joost Breuker
Looking back over 25 yrs of R&D in knowledge acquisition -- particularly mediated by workshops and a journal founded by Brian Gaines -- it is remarkable how topics and perspectives have changed. We started from the assumption that the knowledge acquisition bottleneck was due to the problems of experts expressing their expert knowledge. However, explicitly available knowledge, as, e.g. in handbooks, appeared often sufficient to construct an adequate 'artificial problem solver'. Expert systems became knowledge systems. The bottleneck was rather experienced in modeling the domain knowledge and the reasoning control -- the problem solving method (PSM) -- for automated execution. By developing libraries of reusable PSMs, or implementing shells with built-in PSMs, this bottleneck could be eased. Specifications of domain knowledge lead to the development of ontologies: another source for reuse. Despite the fact that this brought sufficient technology for a mature engineering methodology, little use is made of it in current practice, and developing 'intelligent' software is not much different today from what it was at the beginning of the 1980s. A more impressive heritage of knowledge acquisition R&D is the introduction of technology for building ontologies. These found their way via knowledge management to the architecture of the Semantic Web. In research apparent solutions also bring new problems. Two of these problems are suggested by empirical cognitive science research. The first one is that knowledge as represented in currently available (top-level) ontologies are too simple, because high level concepts may come in design 'patterns': a view that has recently also been taken up in the knowledge acquisition community. The second problem is the fact that despite much empirical research in cognitive psychology, we have insufficient insight in how we acquire new conceptualisations from text. This is a serious bottleneck for an early dream in knowledge acquisition: automated knowledge acquisition.
Keywords: Knowledge acquisition; Ontologies; Problem solving methods; Cognitive science
Situated cognition and knowledge acquisition research BIBAKFull-Text 184-190
  Paul Compton
In the early years of knowledge acquisition research there was considerable discussion about the possibility of obtaining knowledge from experts, based on the ideas of situated cognition. The central idea from situated cognition was that knowledge is only ever created in a context and so cannot be used reliably out of context. These ideas seem to have had little impact on most of the knowledge acquisition research that followed, probably because they seemed to be too negative about the possibilities for knowledge-based systems. This paper suggests that situated cognition can be reinterpreted as making the positive suggestion that if people distinguish between different conclusions in different contexts, they do so because they can identify features that distinguish the contexts. This type of case or context differentiation could be readily integrated with a range of knowledge acquisition frameworks, and experience with Ripple-Down Rules suggests that it provides a very simple way for domain experts and others to easily provide a large amount of knowledge for a system.
Keywords: Situated cognition; Ripple-Down Rules; Knowledge acquisition; Knowledge engineering
Nature, nurture, and knowledge acquisition BIBAKFull-Text 191-194
  Thomas R. Gruber
The nature vs. nurture dualism has framed the modern conversation in biology and psychology. There is an analogous distinction for knowledge acquisition and artificial intelligence. In the context of building intelligent systems, nature means acquiring knowledge by being programmed or modeled that way. Nurture means acquiring knowledge by machine learning from data and information in the world. This paper develops the nature/nurture analogy in light of the history of knowledge acquisition, the current state of the art, and the future of intelligent machines learning from human knowledge.
Keywords: Nature vs. nurture; Artificial intelligence; Knowledge acquisition; Inductive bias; Epigenetics of knowledge
The knowledge acquisition workshops: A remarkable convergence of ideas BIBAKFull-Text 195-199
  Mark A. Musen
Intense interest in knowledge-acquisition research began 25 years ago, stimulated by the excitement about knowledge-based systems that emerged in the 1970s followed by the realities of the "AI Winter' that arrived in the 1980s. The knowledge-acquisition workshops that responded to this interest led to the formation of a vibrant research community that has achieved remarkable consensus on a number of issues. These viewpoints include (1) the rejection of the notion of knowledge as a commodity to be transferred from one locus to another, (2) an acceptance of the situated nature of human expertise, (3) emphasis on knowledge acquisition as the modeling of problem solving, and (4) the pursuit of reusable patterns in problem solving and in domain descriptions that can facilitate both modeling and system implementation. The Semantic Web community will benefit greatly by incorporating these perspectives in its work.
Keywords: Knowledge acquisition; Knowledge-based systems; Semantic web; Workshops and conferences
Knowledge acquisition and the rise of social machines BIBAKFull-Text 200-205
  Nigel Shadbolt
In this issue Brian Gaines (Gaines, 2012) provides a magisterial review of the origins of human kind and human knowledge. It is a reminder that in spite of all our technology it takes a very special type of scholarship to weave such a compelling narrative over such a monumental range of time and material. This article takes a number of strands of Gaines' arguments and presents them in the context of my own, colleagues and the field's research trajectory.
Keywords: Knowledge acquisition; Semantic web; Linked data; Social machines
Knowledge acquisition and the web BIBAKFull-Text 206-210
  Guus Schreiber
Knowledge-acquisition research started in the eighties as a small research community focusing on knowledge-intensive problems in relatively small domains. In this paper we look at the influence the Web has had on knowledge acquisition and vice versa. To this end we discuss in some depth four topics, namely the ontology language OWL, the vocabulary language SKOS, the notion of ontology alignment and the potential of semantic search. Even from this limited selection of research issues related to "Web knowledge' it is safe to conclude that the Web has had a large impact on knowledge acquisition, but also the other way around.
Keywords: Web-based knowledge acquisition; Future of knowledge acquisition; Web ontologies
Reflections on 25+ years of knowledge acquisition BIBAKFull-Text 211-215
  Bob J. Wielinga
In this paper I give a short reflection on Knowledge Acquisition as a subfield of AI and Knowledge Engineering over the last 25 years or so. My major message is that knowledge modeling is an underrated but still important method to reduce the complexity problems that arise in constructing knowledge-based applications. Scale -- as apparent in the Semantic Web -- is another important parameter in recent developments in Knowledge Acquisition: it requires other techniques than those of the 1980s. Natural Language Processing is the most promising way forward, but also the most difficult source of the acquisition of formalized knowledge. I will argue that some of the lessons learned in building knowledge-based systems may carry over to reasoning in the Semantic Web and to knowledge acquisition from natural language web sources.
Keywords: Knowledge acquisition; Knowledge engineering; CommonKads; Knowledge patterns

IJHCS 2013-03 Volume 71 Issue 3

How will the use of graphics affect visual aesthetics? A user-centered approach for web page design BIBAKFull-Text 217-227
  Yang-Cheng Lin; Chung-Hsing Yeh; Chun-Chun Wei
This paper addresses new and significant research issues in web page design in relation to the use of graphics. The original findings include that (a) graphics play an important role in enhancing the appearance and thus users' feelings (aesthetics) about web pages and that (b) the effective use of graphics is crucial in designing web pages. In addition, we have developed a web page design support database based on a user-centered experimental procedure and a neural network model. This design support database can be used to examine how a specific combination of design elements, particularly the ratio of graphics to text, will affect the users' feelings about a web page. As a general rule, the ratio of graphics to text between 3:1 and 1:1 will give the users the best feelings of ease-to-use and clear-to-follow. A web page with a ratio of 1:1 will have the most realistic look, while a ratio of over 3:1 will have the fanciest appearance. The result provides useful insights in using graphics on web pages that help web designers best meet users' specific expectations and aesthetic consistency.
Keywords: Graphics; Web page design; User perception; Visual aesthetics; Kansei Engineering; Neural network
Location matters, especially for non-salient features -- An eye-tracking study on the effects of web object placement on different types of websites BIBAKFull-Text 228-235
  Sandra P. Roth; Alexandre N. Tuch; Elisa D. Mekler; Javier A. Bargas-Avila; Klaus Opwis
Users have clear expectations of where web objects are located on a web page. Studies conducted with manipulated, fictitious websites showed that web objects placed according to user expectations are found faster and remembered more easily. Whether this is also true for existing websites has not yet been examined. The present study investigates the relation between location typicality and efficiency in finding target web objects in online shops, online newspapers, and company web pages. Forty participants attended a within-subject eye-tracking experiment. Typical web object placement led to fewer fixations and participants found target web objects faster. However, some web objects were less sensitive to location typicality, if they were more visually salient and conformed to user expectations in appearance. Placing web objects at expected locations and designing their appearance according to user expectations facilitates orientation, which is beneficial for first impressions and the overall user experience of websites.
Keywords: Mental models; First impression; User expectation; Web design; Eye-tracking; User experience
The impact of candidate display styles for Japanese and Chinese characters on input efficiency BIBAKFull-Text 236-249
  Minghui Sun; Xiangshi Ren; Shumin Zhai; Feng Wang
Entering non-alphabetic text for languages such as Japanese and Chinese into a computer typically consists of typing Roman character-based phonemes and selecting the intended Japanese or Chinese character from a list of homophonic candidates. This paper presents a study of four candidate display styles. Three of them, Vertical, Horizontal, and Compact-Horizontal, are used in commercial products. The fourth style, Matrix, is novel. The candidate display style is studied in conjunction with various manual selection devices including Mouse, Numeric Keys, Spacebar, Cursor Key, and Numeric Keypad. Results show that a great deal of time is taken to choose the correct character in both Chinese and Japanese input. The candidate display style affects both input efficiency and subjective preference. Results also show that the Compact-Horizontal display style outperforms other display styles with a normal keyboard but the Matrix display style is the most efficient when used with a Numeric Keypad due to stimulus-response compatibility and the movement efficiency of such a design.
Keywords: Japanese input; Chinese input; Multiple choice display and selection; Menu; Choice reaction time
The influence of empathy in human-robot relations BIBAKFull-Text 250-260
  Iolanda Leite; André Pereira; Samuel Mascarenhas; Carlos Martinho; Rui Prada; Ana Paiva
The idea of robotic companions capable of establishing meaningful relationships with humans remains far from being accomplished. To achieve this, robots must interact with people in natural ways, employing social mechanisms that people use while interacting with each other. One such mechanism is empathy, often seen as the basis of social cooperation and prosocial behaviour. We argue that artificial companions capable of behaving in an empathic manner, which involves the capacity to recognise another's affect and respond appropriately, are more successful at establishing and maintaining a positive relationship with users. This paper presents a study where an autonomous robot with empathic capabilities acts as a social companion to two players in a chess game. The robot reacts to the moves played on the chessboard by displaying several facial expressions and verbal utterances, showing empathic behaviours towards one player and behaving neutrally towards the other. Quantitative and qualitative results of 31 participants indicate that users towards whom the robot behaved empathically perceived the robot as friendlier, which supports our hypothesis that empathy plays a key role in human-robot interaction.
Keywords: Artificial companions; Social robots; Empathy; Affective interactions; Friendship
Finger-based multitouch interface for performing 3D CAD operations BIBAKFull-Text 261-275
  Srinivasan Radhakrishnan; Yingzi Lin; Ibrahim Zeid; Sagar Kamarthi
The area of multitouch interaction research is at its infancy. The commercial sector has seen an exponential growth in this area with ubiquitous products like Apple i-Phone, i-Pad, and Microsoft surface table. In spite of their popularity, developers are still finding it difficult to extend this novel interface to engineering applications such as computer aided design (CAD), due to insufficient understanding of the factors that affect the multitouch interface interaction when applied to CAD operations. The objective of this research is to (1) outline the key elements of the multitouch interface for CAD, (2) identify the factors affecting the performance of a multitouch enabled CAD modeling environment, and (3) lay a foundation for future research and highlight the directions for extending the multitouch interface for CAD and other engineering applications. To demonstrate specific results we have conducted mouse emulation experiments. We compared the performance of two finger touch-based interaction techniques (drag state finger touch and track state finger touch) and a standard mouse device for 3D CAD modeling operations. The results indicated that both the task completion time and error rates are statistically the same for both the finger touch-based techniques. However, the error concentration observed from the experiments revealed that for the edge selection tasks, the track state technique is more suited than the drag state technique. Both the finger touch-based techniques suffered from precise dimension control while executing the tasks. The inclusion of a grid on the design space for modeling purpose reduced user errors. The mouse device outperformed both the finger touch-based techniques and yielded statistically better results in terms of task completion time and error rates.
Keywords: Multitouch interaction; Computer aided design; Human computer interaction; Gesture-based interaction; Finger-based interaction; Gesture-based modeling
Action graphs and user performance analysis BIBAKFull-Text 276-302
  Harold Thimbleby
A user operating an interactive system performs actions such as "pressing a button' and these actions cause state transitions in the system. However to perform an action, a user has to do what amounts to a state transition themselves, from the state of having completed the previous action to the state of starting to perform the next action; this user transition is out of step with the system's transition. This paper introduces action graphs, an elegant way of making user transitions explicit in the arcs of a graph derived from the system specification. Essentially, a conventional transition system has arcs labeled in the form "user performs action A' whereas an action graph has arcs labelled in the form "having performed action P, the user performs Q.' Action graphs support many modelling techniques (such as GOMS, KLM or shortest paths) that could have been applied to the user's actions or to the system graph, but because it combines both, the modelling techniques can be used more powerfully.
   Action graphs can be used to directly apply user performance metrics and hence perform formal evaluations of interactive systems. The Fitts Law is one of the simplest and most robust of such user modelling techniques, and is used as an illustration of the value of action graphs in this paper. Action graphs can help analyze particular tasks, any sample of tasks, or all possible tasks a device supports -- which would be impractical for empirical evaluations. This is an important result for analyzing safety critical interactive systems, where it is important to cover all possible tasks in testing even when doing so is not feasible using human participants because of the complexity of the system.
   An algorithm is presented for the construction of action graphs. Action graphs are then used to study devices (a consumer device, a digital multimeter, an infusion pump) and results suggest that: optimal time is correlated with keystroke count, and that keyboard layout has little impact on optimal times. Many other applications of action graphs are suggested.
Keywords: Action graph; The Fitts Law; Finite state transition system; Lower bounds on task time; User modelling
Implicit bookmarking: Improving support for revisitation in within-document reading tasks BIBAKFull-Text 303-320
  Chun Yu; Ravin Balakrishnan; Ken Hinckley; Tomer Moscovich; Yuanchun Shi
We explore improving support for revisitation in documents by automatically generating bookmarks based on users' reading history. After showing that dwell time and number of visits are not appropriate for predicting revisitations in documents, we model the high-level reading task as a sequence of reading blocks and recognize long-distance scrolls as separators between them. A long-distance scroll is defined as a continuous scrolling action which causes the document to be navigated beyond a one-page distance. We propose a new technique, called the Head -- Tail (HT) algorithm, to generate bookmarks at the head and the tail of reading blocks, whose validity is quantitatively verified by log data analysis. Two studies were conducted to investigate this HT implicit bookmarking technique. The first is a controlled experiment that compared the HT algorithm to the widely used simple recency algorithm for generating implicit bookmarks, in terms of revisit coverage ability and distance between bookmarks. Results showed the HT algorithm to be superior in both measures. The second is a more ecologically valid study that investigated implicit bookmarking performance in real reading tasks, using Adobe Reader integrated with our implicit bookmarking technique. Results showed that our technique covered 85.1% of revisitations and saved users from 66.0% of long-distance scrolling actions. We end with a discussion of how to encourage users to use implicit bookmarks.
Keywords: Document revisitation; Implicit bookmark; Reading task; Reading block; Document navigation; Scrolling
Factors that affect visually impaired users' acceptance of audio and music websites BIBAKFull-Text 321-334
  Eleanor T. Loiacono; Soussan Djamasbi; Todor Kiryazov
The number of users with visual impairments is on the rise. Companies have an opportunity to increase their reach and revenue by ensuring their websites are accessible to these users. Developing websites around the needs of those with visual impairments is especially critical as the affluent Baby Boomer generation ages and is faced with a multitude of vision problems. Despite this fast growing, web-reliant population, little work has been done to develop a behavioral model that addresses its needs. Grounded in accessibility and acceptance theories, this research proposes a model that predicts Web usage behavior of blind and low-vision users. Our results show that one of the most widely used acceptance models does not predict the adoption behavior of visually impaired users as effectively as a modified model that includes information accessibility. Those with visual impairments decide to revisit a website based, in part, on its accessibility as well as its ease of use and usefulness. These results suggest that traditional acceptance models may predict the behavior of users with visual impairments better when reliability and convenience of access to Information are also considered.
Keywords: Accessibility; Usability; Blind users; Technology acceptance
Smile and the world will smile with you -- The effects of a virtual agent's smile on users' evaluation and behavior BIBAKFull-Text 335-349
  Nicole Krämer; Stefan Kopp; Christian Becker-Asano; Nicole Sommer
Recent studies have demonstrated that people show social reactions when interacting with human-like virtual agents. For instance, human users behave in a socially desirable way, show increased cooperation or apply human-like communication. It has, however, so far not been tested whether users are prone to mimic the artificial agent's behavior although this is a widely cited phenomenon of human-human communication that seems to be especially indicative of the sociality of the situation. We therefore conducted an experiment, in which we analyzed whether humans reciprocate an agent's smile. In a between-subjects design, 104 participants conducted an 8-min small-talk conversation with an agent that either did not smile, showed occasional smiles, or displayed frequent smiles. Results show that although smiling did not have a distinct impact on the evaluation of the agent, the human interaction partners themselves smiled longer when the agent was smiling.
Keywords: Embodied conversational agents; Mimicry; Nonverbal behavior; Smiling; Media equation
Process of design and usability evaluation of a telepsychology web and virtual reality system for the elderly: Butler BIBAKFull-Text 350-362
  Diana Castilla; Azucena Garcia-Palacios; Juana Bretón-López; Ignacio Miralles; Rosa María Baños; Ernestina Etchemendy; Luis Farfallini; Cristina Botella
Butler is a multi-application system based on Internet technology and virtual reality, designed to meet the needs of elderly users. Its objectives are to assist elderly populations in accessing technology and new forms of communication, replicating, as far as possible the way of lineal interaction that this population group had traditionally to interact with information in order to facilitate the first contacts with technology. Butler is equipped with e-mail, videoconferencing, blogging, access to the Internet through a well-known web search engine, image and sound gallery, new contacts searcher, and two virtual reality environments. In this paper we describe Butler's most relevant features taking into account the usability design process and the usability evaluation of the system, which, after pilot testing, have proven to be highly acceptable and satisfactory to users. We also present the results of evaluations pertaining to the iconography used in the program, the navigation and users' help design process, and the first functional prototype, all of which were designed and redesigned with the aid of web heuristics and guidelines for the web design for elderly users. Results suggest important features to be taken into account when designing and developing this sort of application for the elderly.
Keywords: Usability; Virtual reality; Social network; Elderly; Digital divide; Social networking service
Objective versus subjective measures of Paris Metro map usability: Investigating traditional octolinear versus all-curves schematics BIBAKFull-Text 363-386
  Maxwell J. Roberts; Elizabeth J. Newton; Fabio D. Lagattolla; Simon Hughes; Megan C. Hasler
Schematic maps are an important component of assistance for navigating transport networks worldwide. By showing routes as simple straight lines, they reduce the cognitive load of journey planning, and by revealing the underlying structure of networks, they make their key features easier to identify and learn. However, although there are many suggestions for optimizing schematic maps so as to maximize these benefits, to date these have not been directly supported by published usability studies or psychological theory. In this paper, we suggest that there are circumstances in which conventional schematic maps fail to yield benefits, and we compare journey planning using the current official RATP Paris Metro map with an all-curves design which replaces straight lines and corners with gentle curves. Three separate usability studies with slightly different methodologies showed that the journey planning time for the all-curves map was better than the RATP version, with effect sizes ranging from 0.48 to 1.12. Subjective usability ratings were derived from questionnaires, and user preferences, but neither were correlated with objective usability measures. We conclude that (1) in terms of designing schematics, there is no evidence to suggest that any rule-set can be claimed to be a gold-standard, and it is important to match the design rules to the properties of the network, (2) in some circumstances, radical departures from traditional ideas can yield usability benefits, and (3) map usability appears to be distinct from map engagement, although the latter is undoubtedly important in encouraging people fully to make use of navigation aides.
Keywords: Schematic maps; Metro maps; Journey planning; Usability study; Cognitive load; Reasoning

IJHCS 2013-04 Volume 71 Issue 4

The impact of motion dimensionality and bit cardinality on the design of 3D gesture recognizers BIBAKFull-Text 387-409
  Radu-Daniel Vatavu
The interactive demands of the upcoming ubiquitous computing era have set off researchers and practitioners toward prototyping new gesture-sensing devices and gadgets. At the same time, the practical needs of developing for such miniaturized prototypes with sometimes very low processing power and memory resources make practitioners in high demand of fast gesture recognizers employing little memory. However, the available work on motion gesture classifiers has mainly focused on delivering high recognition performance with less discussion on execution speed or required memory. This work investigates the performance of today's commonly used 3D motion gesture recognizers under the effect of different gesture dimensionality and bit cardinality representations. Specifically, we show that few sampling points and low bit depths are sufficient for most motion gesture metrics to attain their peak recognition performance in the context of the popular Nearest-Neighbor classification approach. As a practical consequence, 16x faster recognizers working with 32x less memory while delivering the same high levels of recognition performance are being reported. We present recognition results for a large gesture corpus consisting in nearly 20,000 gesture samples. In addition, a toolkit is provided to assist practitioners in optimizing their gesture recognizers in order to increase classification speed and reduce memory consumption for their designs. At a deeper level, our findings suggest that the precision of the human motor control system articulating 3D gestures is needlessly surpassed by the precision of today's motion sensing technology that unfortunately bares a direct connection with the sensors' cost. We hope this work will encourage practitioners to consider improving the performance of their prototypes by careful analysis of motion gesture representation rather than by throwing more processing power and more memory into the design.
Keywords: Gesture recognition; Gesture dimensionality; Sampling rate; 3D gestures; Classifiers; Bit cardinality; Bit depth; Euclidean distance; Angular cosine distance; Dynamic time warping; Hausdorff; Gesture toolkit
A framework for explaining reliance on decision aids BIBAKFull-Text 410-424
  Kees van Dongen; Peter-Paul van Maanen
This study presents a framework for understanding task and psychological factors affecting reliance on advice from decision aids. The framework describes how informational asymmetries in combination with rational, motivational and heuristic factors explain human reliance behavior. To test hypotheses derived from the framework, 79 participants performed an uncertain pattern learning and prediction task. They received advice from a decision aid either before or after they expressed their own prediction, and received feedback about performance. When their prediction conflicted with that of the decision aid, participants had to choose to rely on their own prediction or on that of the decision aid. We measured reliance behavior, perceived and actual reliability of self and decision aid, responsibility felt for task outcomes, understandability of one's own reasoning and of the decision aid, and attribution of errors. We found evidence that (1) reliance decisions are based on relative trust, but only when advice is presented after people have formed their own prediction; (2) when people rely as much on themselves as on the decision aid, they still perceive the decision aid to be more reliable than themselves; (3) the less people perceive the decision aid's reasoning to be cognitively available and understandable, the less people rely on the decision aid; (4) the more people feel responsible for the task outcome, the more they rely on the decision aid; (5) when feedback about performance is provided, people underestimate both one's own reliability and that of the decision aid; (6) underestimation of the reliability of the decision aid is more prevalent and more persistent than underestimation of one's own reliability; and (7) unreliability of the decision aid is less attributed to temporary and uncontrollable (but not external) causes than one's own unreliability. These seven findings are potentially applicable for the improved design of decision aids and training procedures.
Keywords: Decision support systems; Automation trust; Automation reliance
Subject-dependent biosignal features for increased accuracy in psychological stress detection BIBAKFull-Text 425-439
  Dimitris Giakoumis; Dimitrios Tzovaras; George Hassapis
This paper presents novel subject-dependent biosignal features, with a view towards increasing the effectiveness of automatic psychological stress detection. The features proposed in this work focus on suppressing between-subject variability that typically appears in biosignals like the skin conductance (SC) and the electrocardiogram (ECG), and degrades the performance of relevant emotion recognition (ER) systems. For this purpose, the proposed features employ filtering of input signals, on the basis of "rest signatures' calculated from each subject's baseline recordings. These signatures are biosignal transformations capable to express each individual's baseline deviation from signal templates, which would ideally be applied during rest. The proposed subject-dependent features, extracted from SC and ECG modalities, were found capable to significantly increase automatic stress detection accuracy over a multi-subject (N=24) data set, collected through an experiment of natural stress induction. They provided accuracy at the level of 95%, significantly improved to the respective result (86.05%) taken from common SC and ECG features that have been typically used in the past. They appeared also similarly effective in automatic frustration detection over a further dataset. The results of the present work indicate that the proposed subject-dependent features, can lead to significant advances in the performance of future relevant ER systems.
Keywords: Biosignals; Subject-dependent features; Psychological stress detection; Skin conductance; ECG; Krawtchouk; Legendre; Moments
Evaluating a synthetic talking head using a dual task: Modality effects on speech understanding and cognitive load BIBAKFull-Text 440-454
  Catherine J. Stevens; Guillaume Gibert; Yvonne Leung; Zhengzhi Zhang
The dual task is a data-rich paradigm for evaluating speech modes of a synthetic talking head. Three experiments manipulated auditory-visual (AV) and auditory-only (A-only) speech produced by text-to-speech synthesis from a talking head (Experiment 1 -- single task; Experiment 2 -- dual task), and natural speech produced by a human male similar in appearance to the talking head (Experiment 3 -- dual task). In a dual task, participants perform two tasks concurrently with a secondary reaction time (RT) task sensitive to cognitive processing demands of the primary task. In the primary task, participants either shadowed words or named the superordinate categories to which words belonged under AV (dynamic face with lips moving) or A-only (static face) speech modes. First, it was hypothesized that category naming is more difficult than shadowing. The hypothesis was supported in each experiment with significantly longer latencies on the primary task and slower RT on the secondary task. Second, an AV advantage was hypothesized and supported by significantly shorter latencies for the AV modality on the primary task of Experiment 3 and with partial support in Experiment 1. Third, it was hypothesized that while the AV modality helps it also creates great cognitive load. Significantly longer RT for AV presentation in the secondary tasks supported this hypothesis. The results indicate that task difficulty influences speech perception. Performance on a secondary task can reveal cognitive demand that is not evident in a single task or self-report ratings. A dual task will be an effective evaluation tool in operational environments where multiple tasks are conducted (e.g., responding to spoken directions and monitoring displays) and an implicit, sensitive measure of cognitive load is imperative.
Keywords: Evaluation; Avatar; Dual task; Divided attention; Reaction time; Shadowing
What signal is your inspection team sending to each other? Using a shared collaborative interface to improve shared cognition and implicit coordination in error-detection teams BIBAKFull-Text 455-474
  Paul Benjamin Lowry; Tom L. Roberts; Nicholas C., Jr. Romano
Coordination theory, created in a collaborative HCI context, has long emphasized the importance of implicit coordination. Such coordination is possible through interactivity design that creates shared cognition. Teams experience implicit coordination when they achieve tacit task coordination without direct or purposeful communication of task strategies among the participants, but this is impossible to achieve without shared cognition. Implicit coordination is often more effective than explicit coordination, and teams increasingly lack sufficient time or capabilities to coordinate explicitly; therefore, methods to foster implicit coordination could result in highly practical techniques to improve task performance. Implicit coordination, despite its promise, has not received much attention in the HCI literature. A particular problem we believe has hindered the application of implicit coordination is the dearth of objective measurement of implicit coordination and the related construct shared cognition. Teams have difficulty improving, implementing, and proving the value of implicit coordination without measurement.
   For our theoretical foundation, we use implicit coordination theory (ICT) to explain and predict how a simple shared interface in a group error-detection task can establish formalized group memory and group awareness, which foster the shared cognition necessary for implicit coordination to occur. To test ICT, we demonstrate innovative measurement of implicit coordination and shared cognition -- without intrusive perceptual survey items -- by leveraging measures from signal detection theory (SDT). We use the context of teams performing heuristic data-flow diagramming (HDFD) (which is similar to the Prepare, Collect, and Repair (PCR)-based process of heuristic evaluation) to measure the improved shared cognition and implicit coordination. Namely, we measured shared cognition with SDT's measure of response bias (c); we measured implicit coordination with SDT's measure of discrimination (d'). Supporting our ICT-based predictions, groups operating with a shared interface indeed experienced more shared cognition and implicit coordination -- resulting in higher discrimination, more positive response bias, and more accurate hit rates and false-alarm rates than the control groups. Our results show great promise in making similar predictions, measurements, and improvements in other individual or group inspection tasks, which are prevalent in HCI development research and practice.
Keywords: Implicit coordination; Implicit coordination theory; Shared cognition; Signal detection theory; Collaborative software; Error detection; Explicit coordination
Explaining members' proactive participation in virtual communities BIBAKFull-Text 475-491
  Hsien-Tung Tsai; Peiyu Pai
Understanding members' proactive participation in virtual communities is important to both academics and practitioners. This study extends virtual community research by proposing and testing a model that outlines the antecedents of members' proactive participation behavior and incorporates mediating mechanisms and moderating effects. The findings, based on both qualitative and quantitative data, reveal that social, hedonic, and utilitarian community attributes significantly influence proactive participation through community identification and relationship satisfaction. Furthermore, the conversion of community identification into proactive participation behavior depends on the public recognition of contributions. The authors conclude with some managerial and research implications.
Keywords: Identification; Proactive participation behavior; Recognition of contributions; Satisfaction
Examining the costs of multiple trajectory pointing techniques BIBAKFull-Text 492-509
  P. Quinn; A. Cockburn; J. Delamarche
Pointing techniques that offer users multiple trajectories to a target have the potential to reduce pointing time by allowing a shorter than normal movement distance. However, such techniques potentially introduce additional elements into the pointing task involving identification of the alternative trajectories, assessment of their relative performance, and selection of the one to use. These additional tasks may reduce or negate the benefits of offering shorter paths. To better understand these issues, we developed a methodology for controlling the relative benefits of alternative target trajectories, and used it to evaluate three interfaces -- a 'pointer wrapping' technique that allows the cursor to traverse from one screen edge to the opposing edge, and a system allowing users to choose between multiple cursors in two configurations ('Ninja cursors'). We found that performance with these techniques was significantly worse than that predicted by Fitts' law for a single cursor, suggesting that the additional elements in their use are significant. Detailed analysis of behaviour during acquisitions showed that much of this cost is accrued in the mental preparation that precedes motor action, and in additional volatility in the pointing movements. We discuss how the method and findings may assist those developing enhanced pointing techniques.
Keywords: Fitts' law; Multiple trajectories; Ninja cursors; Pointer wrapping; Search/decision; Torus pointing

IJHCS 2013-05 Volume 71 Issue 5

Analysis and comparison of target assistance techniques for relative ray-cast pointing BIBAKFull-Text 511-532
  Scott Bateman; Regan L. Mandryk; Carl Gutwin; Robert Xiao
Pointing at displays from a distance is becoming a common method of interacting with computer applications and entertainment systems, using devices such as the Wii Remote, the PlayStation Move controller, or the Microsoft Kinect. These systems often implement relative forms of ray-cast pointing, in which the user simply points a hand-held input device towards targets on the screen. Ray-casting interaction is easy for novices to learn and understand, but this technique often suffers from accuracy problems: for example, hand jitter, arm fatigue, calibration drift, or lack of skill can all reduce people's ability to acquire and select on-screen targets. In this paper, we analyse and evaluate the idea of target assistance as a way to address the accuracy problems of ray-cast pointing. Although several assistance schemes have been proposed for mouse-based pointing, these ideas have not been tested in distant-pointing settings, and there is little knowledge available to guide design in this increasingly common interaction scenario. To establish this basic design knowledge, we carried out four studies of relative ray-casting using three different target assistance techniques -- two motor-space techniques (sticky targets and a novel form of target gravity), and one acquisition-feedback technique that combined visual, tactile, and auditory feedback. Our first three studies tested each assistance technique separately, to explore how different parameters for each method affected performance and perceptibility. Our fourth study carried out a direct comparison of the best versions of each technique, and also examined the effects of distractor objects placed in the path to the target. Our studies found that the two motor-space techniques were extremely effective in improving selection accuracy without being highly obvious to users, and that the new gravity-based technique (which attracts the cursor even when it is not over the target) performed best of all. There was no observed effect on performance when the combined acquisition-feedback technique was used. Our studies are the first to comprehensively explore the optimization, performance, and perceptibility of target assistance techniques for relative ray-casting -- our results provide designers with clear guidelines about what methods to use, how to configure the techniques, and what effects can be expected from their use.
Keywords: Ray-cast pointing; Distant pointing; Cursor divergence; Target-assistance; Sticky targets; Target gravity
Interleaving tasks to improve performance: Users maximise the marginal rate of return BIBAKFull-Text 533-550
  Geoffrey B. Duggan; Hilary Johnson; Petter Sørli
Technological developments have increased the opportunity for interleaving between tasks, leading to more interruptions and more choices for users. Three experiments tested the interleaving strategies of users completing simple office-based tasks while adjusting access control privileges to documents. Previous work predicted users would switch tasks to enable them to work on the task that produced the greatest current benefit -- they would maximise the marginal rate of return. Results found that by interleaving between tasks users were able to focus on shorter tasks and that the interleaving decisions were consistent with a strategy of maximising the marginal rate of return. However, interruptions from access control tasks disrupted the processing involved in this task management and led to errors in task selection (Experiment 2) and task performance (Experiment 3). Task interleaving can therefore have costs in security contexts where errors can be catastrophic. Understanding which strategies maximise the marginal rate of return could predict users' task management behaviour.
Keywords: Interleaving; Multitasking; Interruption; Task management; Discretionary access control
An exploration of pen tail gestures for interactions BIBAKFull-Text 551-569
  Feng Tian; Fei Lu; Yingying Jiang; Xiaolong (Luke) Zhang; Xiang Cao; Guozhong Dai; Hongan Wang
In this paper, we performed an exploration on the design and evaluation of pen tail gesture, an interaction method that allows the use of pen tail movement to initiate interactions. Based on our interviews with some designers and researchers who regularly used pen-based tools, we conducted three experiments to establish baseline criteria to distinguish intentional pen tail gestures from incidental pen tail movements, and to understand the basic movement behaviors in pen tail gestures. We developed designs and recognition methods of pen gestures, and implemented three application prototypes based on them. Our research can inspire some new designs of pen-based tools and enrich the design repertoire of pen-based user interfaces.
Keywords: Pen stroke gesture; Pen input
Involving users in the wild -- Participatory product development in and with online communities BIBAKFull-Text 570-589
  Jan Hess; David Randall; Volkmar Pipek; Volker Wulf
In its traditional stance, participatory design (PD) is centred on certain work/application settings and is concerned with the involvement of representative users from these contexts. Nevertheless, current web technologies enable new forms of distributed participation which might allow PD processes to be implemented in a broader and flexible way, but may at the same time raise new issues in relation to participation. In this paper, we report on a Participatory Product Development project, using social technologies, where new issues were raised -- a large population of heterogeneous and globally distributed users; a range of personal and institutional purposes, and the use of these technologies in a largely untested environment. We will reflect on insights that we gathered by through observation of and participation in a software development process driven and influenced by members of an existing online community. By means of participatory observation, analysis of the use of online tools and through semi-structured interviews we identified issues around different notions of timeliness and of process structures that are related to different roles, responsibilities and levels of experience. Our results indicate that the involvement of heterogeneous users in such a context needs to be handled carefully, for the reasons we set out. The role of user representatives acting for a broader online community can become crucial when managing heterogeneity, formulating acceptable compromises and -- perhaps most crucially -- dealing with different professional and 'hobbyist' worldviews. Additionally, we found that the use of standard web technologies only partly support online participation processes. PD 'in the wild' needs to be better embedded in use situations and environments (e.g., by linking discussion and design space, using feedback tools, continuous reflection of the current state of development) rather than refining participatory design as a meta-process separate from use.
Keywords: Participatory design; User-driven software development; End user development
Automatic recognition of object size and shape via user-dependent measurements of the grasping hand BIBAKFull-Text 590-607
  Radu-Daniel Vatavu; Ionut Alexandru Zaiti
An investigation is conducted on the feasibility of using the posture of the hand during prehension in order to identify geometric properties of grasped objects such as size and shape. A recent study of Paulson et al. (2011) already demonstrated the successful use of hand posture for discriminating between several actions in an office setting. Inspired by their approach and following closely the results in motor planning and control from psychology (Makenzie and Iberall, 1994), we adopt a more cautious and punctilious approach in order to understand the opportunities that hand posture brings for recognizing properties of target objects. We present results from an experiment designed in order to investigate recognition of object properties during grasping in two different conditions: object translation (involving firm grasps) and object exploration (which includes a large variety of different hand and finger configurations). We show that object size and shape can be recognized with up to 98% accuracy during translation and up to 95% and 91% accuracies during exploration by employing user-dependent training. In contrast, experiments show less accuracy (up to 60%) for user-independent training for all tested classification techniques. We also point out the variability of individual grasping postures resulted during object exploration and the need for using classifiers trained with a large set of examples. The results of this work can benefit psychologists and researchers interested in human studies and motor control by providing more insights on grasping measurements, pattern recognition practitioners by reporting recognition results of new algorithms, as well as designers of interactive systems that work on gesture-based interfaces by providing them with design guidelines issued from our experiment.
Keywords: Hand posture; Grasping; Prehension; Object recognition; Experiment; Shape recognition; Size recognition; Measurements; Data glove; Gestures
Haptics and graphic analogies for the understanding of atomic force microscopy BIBAKFull-Text 608-626
  Guillaume Millet; Anatole Lécuyer; Jean-Marie Burkhardt; Sinan Haliyo; Stéphane Régnier
This paper aims to evaluate the benefits of using virtual reality and force-feedback to help teaching nanoscale applications. We propose a teaching aid that combines graphic analogies and haptics intended to improve the grasp of non-intuitive nanoscale phenomena for people without prior knowledge of nanophysics. We look specifically at the most important nanophysical phenomenon, namely, the behavior of the probe of an Atomic Force Microscope (AFM) as it approaches a sample. The results from experiments carried out with 45 students indicate that a "magnet-spring' analogy helped beginners to establish the link between the behavior of a probe and its force -- distance curve. The addition of haptic feedback increased focus about forces and improved the interpretation of the effect of cantilever stiffness. Haptic feedback and the analogical representation were very much appreciated by the subjects and had an impact on the construction of a mental model. Taken together, our results show a positive influence of using haptic feedback and graphic analogies, especially when students are first exposed to the notions that are in effect at the nanoscale.
Keywords: Haptic I/O; Analogies; Education; Micro/nano technology; Human factors
Eyes-free interaction with free-hand gestures and auditory menus BIBAKFull-Text 627-640
  Raine Kajastila; Tapio Lokki
Auditory interfaces can overcome visual interfaces when a primary task, such as driving, competes for the attention of a user controlling a device, such as radio. In emerging interfaces enabled by camera tracking, auditory displays may also provide viable alternatives to visual displays. This paper presents a user study of interoperable auditory and visual menus, in which control gestures remain the same in the visual and the auditory domain. Tested control methods included a novel free-hand gesture interaction with camera-based tracking, and touch screen interaction with a tablet. The task of the participants was to select numbers from a visual or an auditory menu including a circular layout and a numeric keypad layout. Results show, that even with participant's full attention to the task, the performance and accuracy of the auditory interface are the same or even slightly better than the visual when controlled with free-hand gestures. The auditory menu was measured to be slower in touch screen interaction, but questionnaire revealed that over half of the participants felt that the circular auditory menu was faster than the visual menu. Furthermore, visual and auditory feedback in touch screen interaction with numeric layout was measured fastest, touch screen with circular menu second fastest, and the free-hand gesture interface was slowest. The results suggest that auditory menus can potentially provide a fast and desirable interface to control devices with free-hand gestures.
Keywords: Free-hand gestures; Auditory display; Auditory menu; Spatial sound; Eyes free; Interaction

IJHCS 2013-06 Volume 71 Issue 6

AffectButton: A method for reliable and valid affective self-report BIBAKFull-Text 641-667
  Joost Broekens; Willem-Paul Brinkman
In this article we report on a new digital interactive self-report method for the measurement of human affect. The AffectButton (Broekens and Brinkman, 2009. ACII 2009: IEEE) is a button that enables users to provide affective feedback in terms of values on the well-known three affective dimensions of pleasure (valence), arousal and dominance. The AffectButton is an interface component that functions and looks like a medium-sized button. The button presents one dynamically changing iconic facial expression that changes based on the coordinates of the user's pointer in the button. To give affective feedback the user selects the most appropriate expression by clicking the button, effectively enabling 1-click affective self-report on 3 affective dimensions. Here we analyze 5 previously published studies, and 3 novel large-scale studies (n=325, n=202, n=128). Our results show the reliability, validity, and usability of the button for acquiring three types of affective feedback in various domains. The tested domains are holiday preferences, real-time music annotation, emotion words, and textual situation descriptions (ANET). The types of affective feedback tested are preferences, affect attribution to the previously mentioned stimuli, and self-reported mood. All of the subjects tested were Dutch and aged between 15 and 56 years. We end this article with a discussion of the limitations of the AffectButton and of its relevance to areas including recommender systems, preference elicitation, social computing, online surveys, coaching and tutoring, experimental psychology and psychometrics, content annotation, and game consoles.
Keywords: Affective self-report; Novel interface component; User studies; Emotion; Affective labeling tool
Introducing PEGI: A usability process for the practical evaluation of Geographic Information BIBAKFull-Text 668-678
  M. Brown; S. Sharples; J. Harding
As the use of Geographic Information (GI) is becoming more widespread, the usability of GI is being recognised as an important issue. However, exploring the usability of information products brings with it a range of problems that are not easily handled by traditional user centred design methods. This paper describes the Practical Evaluation of Geographic Information (PEGI) process, which consists of a series of usability research methods that have been modified for use with GI. Two case studies are also presented, describing the application of PEGI within a commercial product development process. The advantages and disadvantages of the PEGI process are discussed as well as plans for future research in this area. The potential value of this approach is also described in terms of cost-benefit, concluding that a £3000 evaluation process could help produce benefits of over £40,000 a year in cost savings and increased sales.
Keywords: Usability; Geographic Information; Expert evaluation; User centred design
Touch gestures in communicating emotional intention via vibrotactile stimulation BIBAKFull-Text 679-690
  Jussi Rantala; Katri Salminen; Roope Raisamo; Veikko Surakka
Remote communication between people typically relies on audio and vision although current mobile devices are increasingly based on detecting different touch gestures such as swiping. These gestures could be adapted to interpersonal communication by using tactile technology capable of producing touch stimulation to a user's hand. It has been suggested that such mediated social touch would allow for new forms of emotional communication. The aim was to study whether vibrotactile stimulation that imitates human touch can convey intended emotions from one person to another. For this purpose, devices were used that converted touch gestures of squeeze and finger touch to vibrotactile stimulation. When one user squeezed his device or touched it with finger(s), another user felt corresponding vibrotactile stimulation on her device via four vibrating actuators. In an experiment, participant dyads comprising a sender and receiver were to communicate variations in the affective dimensions of valence and arousal using the devices. The sender's task was to create stimulation that would convey unpleasant, pleasant, relaxed, or aroused emotional intention to the receiver. Both the sender and receiver rated the stimulation using scales for valence and arousal so that the match between sender's intended emotions and receiver's interpretations could be measured. The results showed that squeeze was better at communicating unpleasant and aroused emotional intention, while finger touch was better at communicating pleasant and relaxed emotional intention. The results can be used in developing technology that enables people to communicate via touch by choosing touch gesture that matches the desired emotion.
Keywords: Haptics; Mediated social touch; Tactile communication; Mobile devices; Emotions; Affective interaction
MTi: A method for user identification for multitouch displays BIBAKFull-Text 691-702
  Bojan Blazica; Daniel Vladušic; Dunja Mladenic
This paper describes MTi, a biometric method for user identification on multitouch displays. The method is based on features obtained only from the coordinates of the 5 touchpoints of one of the user's hands. This makes MTi applicable to all multitouch displays large enough to accommodate a human hand and detect 5 or more touchpoints without requiring additional hardware and regardless of the display's underlying sensing technology. MTi only requests that the user places his hand on the display with the fingers comfortably stretched apart. A dataset of 34 users was created on which our method reported 94.69% identification accuracy. The method's scalability was tested on a subset of the Bosphorus hand database (100 users, 94.33% identification accuracy) and a usability study was performed.
Keywords: Multitouch; User identification; Biometrics; Identity-enabled surfaces
Modelling human tutors' feedback to inform natural language interfaces for learning BIBAKFull-Text 703-724
  Kaska Porayska-Pomsta; Chris Mellish
Modelling human tutors' socio-linguistic abilities computationally is necessary to underpin human-computer educational interactions with best pedagogic practices and to enhance the naturalness of such interactions. In this paper we present a computational model of tutorial feedback selection based on the context of the immediate situation for which the feedback is selected as well as on politeness considerations shown to be of importance to increasing pedagogical efficacy of computer assisted learning (Wang et al., 2008). The model is based on empirical studies with human tutors and on extensive linguistic analysis of human tutorial dialogues collected with the specific aim to inform the implementation of a natural language tutorial dialogue interface. The evaluation of the model, involving the comparison of its output with the linguistic responses produced by a human tutor, demonstrates the model's plausibility and highlights future directions for improving natural language human-computer interactions for educational purposes.
Keywords: Tutorial interactions; Politeness; Believable natural language interfaces
EISEval, a generic reconfigurable environment for evaluating agent-based interactive systems BIBAKFull-Text 725-761
  Chi Dung Tran; Houcine Ezzedine; Christophe Kolski
The evaluation of interactive systems has been an active subject of research for many years. Many methods have been proposed, but most of them do not take the architectural specificities of an agent-based interactive system into account, nor do they focus on the link between architecture and evaluation. In this paper, we present an agent-based architecture model for interactive systems. Then, based on this architecture, we propose a generic, reconfigurable evaluation environment, called EISEval, designed and developed to help evaluators analyze and evaluate certain aspects of interactive systems in general and of agent-based architecture interactive systems in particular: User Interface (UI), non-functional properties (e.g., response time, complexity) and user characteristics (e.g., abilities, preferences, progress). System designers can draw useful conclusions from the evaluation results to improve the system. This environment was applied to evaluate an agent-based interactive system used to supervise an urban transport network in a study organized in laboratory.
Keywords: Evaluation; User interface; Electronic informer; Ergonomic criteria; Agent-based architecture; Interactive systems; Human-computer interaction (HCI)

IJHCS 2013-07 Volume 71 Issue 7/8

Investigating the effects of physical and virtual embodiment in task-oriented and conversational contexts BIBAKFull-Text 763-774
  Laura Hoffmann; Nicole C. Krämer
Studies comparing physically embodied robots with virtually embodied screen characters (e.g. Powers et al., 2007. Jung and Lee, 2004.) have resulted in unsimilar findings with respect to subjective (users' evaluations) as well as objective (e.g. task performance of the users) measurements. The comparability of these results is mainly impeded by the use of different robots, a variety of virtual embodiments (video recording, computer simulation, animated characters, etc.) and different interaction scenarios. To overcome this problem, an experimental study was conducted in which the embodiment of an artificial entity was varied systematically as well as the type of interaction using a 2Ã -- 2 between subjects design (N=83). Participants interacted with either a robot or a virtual representation of this robot (on a screen) in a task-oriented or a persuasive -- conversational scenario. The results revealed that participants perceived the robot as more competent than the virtual character in the task-oriented scenario, but the opposite was true for the persuasive -- conversational scenario. Furthermore, participants in the task-oriented scenario felt better after the interaction than participants who had a persuasive -- conversational interaction with the artificial entity, regardless of its embodiment. No statistically significant differences between the experimental conditions emerged with respect to objective measures (persuasion and task performance). Various explanations for these findings are discussed and implications for the application of robots and virtual characters are derived.
Keywords: Robot; Virtual character; Comparison study; Embodiment; Evaluation
Customizing by doing for responsive video game characters BIBAKFull-Text 775-784
  Andrea Kleinsmith; Marco Gillies
This paper presents a game in which players can customize the behavior of their characters using their own movements while playing the game. Players' movements are recorded with a motion capture system. The player then labels the movements and uses them as input to a machine learning algorithm that generates a responsive behavior model. This interface supports a more embodied approach to character design that we call "Customizing by Doing'. We present a user study which shows that using their own movements made the users feel more engaged with the game and the design process, due in large part to a feeling of personal ownership of the movement.
Keywords: Interactive machine learning; Embodied design; Body expressions; Video game characters
Design and evaluation of 3D selection techniques based on progressive refinement BIBAKFull-Text 785-802
  Felipe Bacim; Regis Kopper; Doug A. Bowman
Issues such as hand and tracker jitter negatively affect user performance with 3D selection techniques based on the ray-casting metaphor. This makes it difficult for users to select objects that have a small visible area, since small targets require high levels of precision. We introduce an approach to address this issue that uses progressive refinement of the set of selectable objects to reduce the required precision of the task. We present three exemplar techniques (sphere-casting refined by QUAD menu (SQUAD), discrete zoom, and continuous zoom) and derive a preliminary design space for progressive refinement from their characteristics. We explore the trade-offs between progressive refinement and immediate selection techniques in two studies: first comparing SQUAD to ray-casting; and second comparing the zooming techniques to ray-casting. In both studies, an analytical evaluation based on a distal pointing model and an empirical evaluation demonstrates that progressive refinement selection can provide significant benefits compared to immediate techniques. In the first study, SQUAD was much more accurate than ray-casting, and SQUAD was faster than ray-casting with small targets and less cluttered environments. The issue with SQUAD, however, is that it requires all selectable objects to be visually distinct. The zooming techniques address this issue by exploring other areas of the progressive refinement design space. They allow users to use the spatial relationships among objects as criteria for selection and to increase precision without requiring precision in pointing. The results of the second study show that while the zooming techniques were significantly slower than ray-casting, accuracy was much higher. Additionally, depending on the size of the target, users chose not to use zoom and, therefore, performed as fast as with ray-casting.
Keywords: 3D interaction; Selection; Performance models; User studies
To TUI or not to TUI: Evaluating performance and preference in tangible vs. graphical user interfaces BIBAKFull-Text 803-820
  Oren Zuckerman; Ayelet Gal-Oz
Tangible user interfaces (TUIs) are often compared to graphical user interfaces (GUIs). However, the existing literature is unable to demonstrate clear advantages for either interface, as empirical studies yielded different findings, sometimes even contradicting ones. The current study set out to conduct an in-depth analysis of the strengths and weaknesses of both interfaces, based on a comparison between similar TUI and GUI versions of a modeling and simulation system called "FlowBlocks'. Results showed most users preferred the TUI version over the GUI version. This is a surprising finding, considering both versions were equivalent in regard to most performance parameters, and the TUI version was even perceived as inferior to the GUI version in regard to usability. Interviews with users revealed this preference stemmed from high levels of stimulation and enjoyment, derived from three TUI properties: physical interaction, rich feedback, and high levels of realism. Potential underlying mechanisms for these findings and practical implications are discussed.
Keywords: TUI; GUI; Tangible; Physical; Graphical; Interaction design
Assessing physical workload for human-robot peer-based teams BIBAKFull-Text 821-837
  Caroline E. Harriott; Tao Zhang; Julie A. Adams
Peer-based human-robot teams involve both teammates working in the same physical space and contributing to the same goals. Predictions of human performance based upon environmental, internal, task and organizational influences have proven useful, but these predictive methods have not yet been proven to apply to human-robot peer-based team situations. Physical workload is an important component of overall workload and influences human performance. The presented research examines physical workload metrics, appraises predictive models of physical workload, and investigates the impact of human-robot peer-based teaming situations on physical workload. Two evaluations are presented. The Guided evaluation required participants to follow guided instructions provided by a partner, either a remotely located human or a locally situated robot. The Collaborative evaluation required collaboration and teaming with joint decisions with either the locally situated human or robot partner. The results from both evaluations show that overall workload and subjectively rated physical workload was lower for the human-robot teams than the human-human teams; however, the physiologically measured physical workload was higher for the human-robot teams. The lack of a collocated human partner during the Guided evaluation did not affect the workload results. The modeling techniques and empirical measures used in the evaluations can be extended to other human-robot team situations.
Keywords: Human-robot peer-based teams; Physical workload; Human performance moderator functions
On the design of a Dual-Mode User Interface for accessing 3D content on the World Wide Web BIBAKFull-Text 838-857
  Jacek Jankowski; Stefan Decker
The World Wide Web, today's largest and most important online information infrastructure, does not support 3D content and, although various approaches have been proposed, there is still no clear design methodology for user interfaces that tightly integrate hypertext and interactive 3D graphics. This paper presents a novel strategy for accessing information spaces, where hypertext and 3D graphics data are simultaneously available and interlinked. We introduce a Dual-Mode User Interface that has two modes between which a user can switch anytime: the driven by simple hypertext-based interactions "hypertext mode', where a 3D scene is embedded in hypertext and the more immersive "3D mode', which immerses the hypertextual annotations into the 3D scene. A user study is presented, which characterizes the interface in terms of its efficiency and usability.
Keywords: Hypertext; 3D Graphics; 3D Web; User Interface

IJHCS 2013-09 Volume 71 Issue 9

Introduction to the special issue on social networks and ubiquitous interactions BIBFull-Text 859-861
  Vassilis Kostakos; Mirco Musolesi
Why do people share their context information on Social Network Services? A qualitative study and an experimental study on users' behavior of balancing perceived benefit and risk BIBAKFull-Text 862-877
  Haein Lee; Hyejin Park; Jinwoo Kim
Despite the rapid growth of context-aware systems and ubiquitous computing, the factors influencing users' decision to share their context information in a social setting are poorly understood. This study aims to clarify why users share their context information in social network service (SNS), even while they are concerned with the potential risk at the same time. Drawing on the diverse theories of self-disclosure, we take an approach that the consideration of benefit encourages users to endure the existence of risk, and that users actively adjust the way they share their information to optimize the level of benefit and risk. In a qualitative study, we examined what kinds of risks and benefits exist in context information sharing situations and how users control them. An experiment was conducted using stimuli that simulate the actual use of SNS to investigate the effect of various context types and control types on users' expected benefit and risk and their intention to share. The results showed that both expected benefit and expected risk influenced users' intention to share. More interestingly, the effect of expected benefit was found to be stronger than that of expected risk. Moreover, different privacy control strategies were found to have induced different effects on the expected benefit and expected risk. Implications and limitations of this study were proposed at the end of this study.
Keywords: Context information sharing; Social context; Privacy control; Social privacy; Social network service
Already up? using mobile phones to track & share sleep behavior BIBAKFull-Text 878-888
  Alireza Sahami Shirazi; James Clawson; Yashar Hassanpour; Mohammad J. Tourian; Albrecht Schmidt; Ed H. Chi; Marko Borazio; Kristof Van Laerhoven
Users share a lot of personal information with friends, family members, and colleagues via social networks. Surprisingly, some users choose to share their sleeping patterns, perhaps both for awareness as well as a sense of connection to others. Indeed, sharing basic sleep data, whether a person has gone to bed or waking up, informs others about not just one's sleeping routines but also indicates physical state, and reflects a sense of wellness. We present Somnometer, a social alarm clock for mobile phones that helps users to capture and share their sleep patterns. While the sleep rating is obtained from explicit user input, the sleep duration is estimated based on monitoring a user's interactions with the app. Observing that many individuals currently utilize their mobile phone as an alarm clock revealed behavioral patterns that we were able to leverage when designing the app. We assess whether it is possible to reliably monitor one's sleep duration using such apps. We further investigate whether providing users with the ability to track their sleep behavior over a long time period can empower them to engage in healthier sleep habits. We hypothesize that sharing sleep information with social networks impacts awareness and connectedness among friends. The result from a controlled study reveals that it is feasible to monitor a user's sleep duration based just on her interactions with an alarm clock app on the mobile phone. The results from both an in-the-wild study and a controlled experiment suggest that providing a way for users to track their sleep behaviors increased user awareness of sleep patterns and induced healthier habits. However, we also found that, given the current broadcast nature of existing social networks, users were concerned with sharing their sleep patterns indiscriminately.
Keywords: Sleep; Alarm clock; Social network; Behavior; Awareness; Mobile phone
Enriching in-person encounters through social media: A study on family connectedness for the elderly BIBAKFull-Text 889-899
  Raymundo Cornejo; Mónica Tentori; Jesús Favela
Social media sites have become immensely popular. In 2010 it was estimated that Americans spent a quarter of their online time using social networking sites (SNSs) and blogs. Prior studies have shown how people spend more time socializing through digital communication services such as SNSs reducing face-to-face interaction. Individuals limited offline interactions cause a sense of self-perception of being less socially involved. In this paper we explore how the use of an ubiquitous system we developed, Tlatoque, is able to adapt and move the SNS's social capital outside the desktop into a domestic setting to support older adults' offline interactions with their family. The findings of a 21 week deployment study uncovered the offline practices surrounding the use of Tlatoque and its social implications toward the existing family ties (n=30). Results qualitatively indicate that the content shared in SNSs strengthens older adults' social network by enriching and complementing traditional social engagements such as those conducted over the phone or in-person.
Keywords: Ambient social network system; Elderly; In-person encounters; Sentient displays
Good Samaritans on social network services: Effects of shared context information on social supports for strangers BIBAKFull-Text 900-918
  Sangwon Bae; Jinkyu Jang; Jinwoo Kim
Technological developments in smart phones and various sensors have been growing at a rapid pace, which leads people to share their context information with other users and support strangers in social network services (SNS). This allows us to study the effects of shared context information on socially supportive behaviors of individuals (Good Samaritans) in SNS. Our aim of this study is to investigate the pattern of social support amongst strangers in SNS. We aim to find out which types and forms of context information induce high levels of willingness to provide social support among strangers. We focus on four different types of context information (location, activity, emotion, or physical environment), which vary by degree of self-disclosure. We also investigated two forms of context information (subjective vs. objective), which differ depending on the provision of human interpretation.
   In order to achieve our research goals, we first constructed a causal model between context information and social support mediated by the theory of mind, which consists of simulation theory (empathy) and theory theory (rational reasoning). To verify the model, we conducted two exploratory pre-studies and a controlled main experiment. Our results indicated that types and forms of context information affect social support, simulation theory and theory theory. First, we found that a high level of self-disclosure positively effects social support. Context information in the subjective form induced more social supports compared to the objective form even though the information content itself is the same. Emotional context information presented in the subjective form has the strongest positive effect on social support. Furthermore, a high level of self-disclosure was found to positively affect context form's effect on simulation theory and social supports. In regard to theory theory, we discovered that high levels of self-disclosure have a positive effect.
   Both practical and theoretical implications of the study results have been presented. Theoretically, a conceptual model of the effects of context information on intention to provide social supports has been proposed and empirically verified. Practically, the interplay between context information types and forms can be utilized to construct social network services efficiently promoting social supports among fellow users. This paper ends with study limitations and implications.
Keywords: Context information; Social support; Theory of mind; Simulation theory; Theory theory; Self-disclosure; Social network services
A novel mobile device user interface with integrated social networking services BIBAKFull-Text 919-932
  Yanqing Cui; Mikko Honkala
Modern mobile devices support accessing Web-based social networking services from the user interface (UI) of Web browsers, applications, and mobile widgets. While effectively accessing these services, people may find it tedious to switch between multiple user interfaces in order to be aware of the latest content. Aiming for an improved user experience, we experimented with integration of these services into mobile devices' main user interface. The integrated content is presented beyond application silos and automatically filtered to highlight the relevant elements. A mobile system called LinkedUI was developed and deployed in one lab test and one field study. Three findings emerge from these studies. Firstly, it is feasible to construct an alternative device UI that supports integration of Web content across applications and services via hyperlinking. Time, publisher (e.g., contacts), content types, and geographical locations are key dimensions for association of content. Secondly, the alternative device UI enables better usability of accessing social networking services than accessing them from individual Web sites on mobile devices. It helps people to be aware of the latest content during microbreaks. Thirdly, automatic filtering, on the basis of one user's data, is one promising approach to identifying relevant content. Given filtered content, most people using the automatic filtering approved the functionality and experienced a better sense of control that is arguably due to the reduced information volume.
Keywords: Mobile Web; Social networking services; Hypertext navigation; Automatic filtering; User experience

IJHCS 2013-10 Volume 71 Issue 10

Human computation: Image metadata acquisition based on a single-player annotation game BIBAKFull-Text 933-945
  Jakub Šimko; Michal Tvarozek; Mária Bieliková
Effective acquisition of descriptive semantics for images is still an open issue today. Crowd-based human computation represents a family of approaches able to provide large scale metadata with decent quality. Within this field, games with a purpose (GWAP) have become increasingly important, as they have the potential to motivate contributors to the process through entertainment. However, the existing solutions are weak, when specific metadata are needed. In this work, we present a game with a purpose called PexAce, which utilizes manpower to collect tags characterizing a set of given images. Using novel game mechanics, the game is a single-player, less prone to cold-start problems and suitable for deployment in the domain of personal imagery. As our experiments show, the game delivers tags that characterize images with high precision (using a posteriori expert evaluation and evaluation against the gold standard: the extended Corel 5k dataset). We also employ the game in the domain of personal images, where very specific metadata are needed for their proper organization (person names, places, events) and show, that the game is able to collect even these kinds of metadata. We show that the key to higher quality metadata lies in combining the fun factor of the game with motivation for personal gain.
Keywords: Human computation; Game with a purpose; Metadata; Crowdsourcing; Image; Semantics
Visualizing the application of filters: A comparison of blocking, blurring, and colour-coding whiteboard information BIBAKFull-Text 946-957
  Rasmus Rasmussen; Morten Hertzum
Through a mixed-design experiment we compare how emergency-department clinicians perform when solving realistic work tasks with an electronic whiteboard where the application of information filters is visualized either by blocking, colour-coding or blurring information. We find that clinicians perform significantly faster and with less effort and temporal demand when using the blocking interface. However, we also find that the colour-coding interface provides clinicians with a better overview of the information displayed by the electronic whiteboard. The blurring interface did not perform as well as previous research has shown and we discuss the differences between these results and ours. Finally, we find that the clinicians worked much less in parallel than we had expected and discuss the reasons for this.
Keywords: Information visualization; Filters; Colour-coding; Semantic depth of field; Electronic whiteboards
Faces and Pictures: Understanding age differences in two types of graphical authentications BIBAKFull-Text 958-966
  James Nicholson; Lynne Coventry; Pam Briggs
Recall of knowledge-based authentication codes such as passwords and PINs can be problematic, particularly for older adults given the known memory decline associated with ageing. We explored the extent to which recognition-based Graphical Authentication Systems were effective alternatives to PINs and passwords in a study in which users were asked to commit several different codes to memory and recall them at different time periods. Populations of younger and older adults were given face-based and picture-based authentication codes to remember over the course of three weeks. Results show a pronounced age effect, with younger participants outperforming older participants. Older participants fared better with the face-based system over the picture-based system while younger participants exhibited the opposite effect. A significant performance drop was observed for older participants over time, as additional codes were introduced.
Keywords: Graphical authentication systems; Graphical passwords; Authentication; Older adults
Emotional clouds: Showing arousal and valence through the movement and darkness of digital cartoonish clouds BIBAKFull-Text 967-977
  Jesús Ibáñez
While nowadays the most usual way to show emotions in digital contexts is via virtual characters, its use may raise false expectations (the user attributes human abilities to the virtual character). This paper proposes and explores an approach to express emotions which intends to minimize the user's expectations by using a non-anthropomorphic model. Emotions are represented in terms of arousal and valence dimensions. They are visualized in a simple way through the behaviour and appearance of a series of cartoonish clouds. In particular, the arousal value is expressed through the movement of these clouds (controlled by a flocking algorithm), while the valence value is expressed through their degree of darkness. Furthermore, the paper describes a user experiment which investigated whether the arousal and valence expressed by our model are appropriately interpreted by the users or not. The results suggest that movement and darkness are interpreted as arousal and valence respectively and that they are independent of each other.
Keywords: Arousal; Valence; Emotions; Movement; Flocking; Darkness; Clouds
How level of realism influences anxiety in virtual reality environments for a job interview BIBAKFull-Text 978-987
  Joung Huem Kwon; John Powell; Alan Chalmers
This study describes how the level of graphical realism required in a virtual social simulation setting can be therapeutically useful in reducing job interview anxiety through exposure. We developed a virtual job interview simulation at a university career service to help student populations faced with the prospect of their first job interview. The virtual job interview simulation can deliver a realistic mock job interview within a high-quality immersive system that is similar to professional virtual reality (VR) systems. We conducted two experimental studies with a common theme: the role of graphical reality of the virtual interviewer and the immersive visual display in the virtual job interview simulation. The results are presented in this study based on a psycho-physiological approach, revealing variation in the distribution of participants' anxiety state across various VR conditions. The overall conclusion of this study is that the sense of anxiety is less correlated to the graphical realism in VR environment even though the more graphically detailed the virtual human was, the more it provoked a sense of presence. In addition, at least some degree of physical immersion is needed to maintain anxiety levels over the course of VR exposure.
Keywords: Human computer interaction; Virtual reality exposure therapy; Virtual human; Anxiety; Presence; Immersion
Communicative modalities for mobile device interaction BIBAKFull-Text 988-1002
  Eli R. Hooten; Sean T. Hayes; Julie A. Adams
An investigation of communicative modalities in relation to mobile device interaction while walking is presented. A user evaluation compared three communicative modality conditions: Auditory, Visual, and Mixed (a redundant audio-visual modality). Findings determined that redundant audio-visual modalities are as good as (but no better than) the visual modality, and both are superior to the auditory modality. Reported findings also determined that walking speeds are unaffected by communicative modality.
   Shape drawing tasks were performed on a touch screen using each modality, and a robust, novel error calculation algorithm was developed to assess the drawing error between the user input and the desired shapes. Drawing error was determined to be significantly higher with the Auditory condition, but drawing speed was unaffected by the communicative modality.
   The evaluation finds that the visual modality should be leveraged as the primary communicative modality for mobile, map-based interfaces. The drawing error algorithm can be applied to any domain that requires determining precise matchings to known information when drawing.
Keywords: Mobile device interaction; Touch interaction; Communicative modalities; Input recognition
TimelyPresent: Connecting families across continents BIBAKFull-Text 1003-1011
  H. Kim; A. Monk; G. Wood; M. Blythe; J. Wallace; P. Olivier
TimelyPresent is a single purpose information appliance for asynchronous messaging to connect three-generation families whose members need to keep in touch across large distances and in different time zones. The touch screen devices are used in pairs situated in the homes of family members. A user at one end can create a short video clip that is represented as a gift-wrapped present to be sent to the home of another family member. To reinforce the present metaphor the design deliberately confounds common assumptions made about electronic devices in that the present having been sent is no longer accessible to the sender and is delayed so that it arrives at the local time that it was recorded. The paper first describes the process by which this design was derived from the qualitative data in the form of quotes from an open-ended probe study. This process served to preserve the richness of the information in the quotes, while at the same time providing 'requirements' for design. The main part of the paper describes the results from a 2-month, four-family field study of the device. Logs recording the behaviour of users of TimelyPresent, transcripts of 15 interviews, and 133 presents created by the participants were analysed. Analysis of the logs showed that the families needed to preview presents before sending them and repeatedly revisit them after receipt. The analysis of the content of the presents demonstrated the need for the 'forward' and 'backward' facing cameras, now commonly provided in tablets and phones. A forward facing camera is needed because 70% of the presents featured a recording of someone doing something. Other categories of topic were simple "I am thinking of you' messages (15%), "things I've done' (8%), and requests for action (7%). Analysis of the interviews confirmed many of the social needs identified in previous work in this area as well as the value of the present metaphor and its ability to support playful use that enhances subsequent conversations using synchronous media.
Keywords: Media gifts; Asynchronous communication; Family

IJHCS 2013-11 Volume 71 Issue 11

Coping tactics employed by visually disabled users on the web BIBAKFull-Text 1013-1025
  Markel Vigo; Simon Harper
Interaction on the Web is often problematic for visually disabled users. In order to analyse how visually disabled users deal with problematic situations we carried out a secondary analysis of 2 independent datasets containing the interaction of 24 users. As a result, we determine the situations in which coping occurs including uncertainty, reduced mobility, confusion and overload, and identify 17 tactics employed to overcome these situations, being impulsive clicking, exploration tactics and re-doing some of the most noteworthy. These tactics are novel in that they are contextualised and complete: their presence denotes the presence of specific problems. Therefore, these tactics are behavioural markers of cognitive processes that indicate problematic situations. We highlight the importance of these behavioural markers for designers and tools in order to remove the need to cope, evaluate accessibility-in-use and inform navigation models.
Keywords: Behavioural sciences; Web tactics; Behavioural strategies; Coping tactics; Blind users; Low vision; Screen readers; Screen magnifiers
PLANT: A pattern language for transforming scenarios into requirements models BIBAKFull-Text 1026-1043
  Ye Wang; Liping Zhao; Xinyu Wang; Xiaohu Yang; Sam Supakkul
Despite their important role in software development, scenarios suffer from several major drawbacks. To remedy these drawbacks, this paper presents a pattern language as means of connection between scenarios and their target models. The pattern language contains four patterns: Establishing the Story Line, Elaborating Things that Change, Identifying Agents and Their Interactions, and Unraveling the Goal and its Subgoals. Each of these patterns connects one aspect of a given scenario to a conceptual model and offers guidelines for converting this aspect into a target model. Together, these four patterns transform a scenario into four interrelated requirements models. These scenario aspects are identified according to the concepts of scenarios used in both Cognitive Science and Requirements Engineering. This paper first lays out the theoretical foundation of this pattern language and then gives a detailed description, illustration and assessment of this language.
Keywords: Multi-perspective scenario modeling; Scenario metamodel; Scenario models; Scenario-to-model transformation; Patterns; Pattern languages
The "Map' in the mental map: Experimental results in dynamic graph drawing BIBAKFull-Text 1044-1055
  Daniel Archambault; Helen C. Purchase
Preserving the mental map is frequently cited by dynamic graph drawing algorithm designers as an important optimization criterion. There have been a number of definitions for mental map preservation and many different algorithmic approaches to drive dynamic graph drawing to satisfy these definitions. One of the most frequently used definitions is that of Coleman and Parker where "the placement of existing nodes and edges should change as little as possible when a change is made to the graph.' A number of experiments have been run to test the effectiveness of this definition from a usability perspective. To date, no experiment has found conclusive evidence that supports the effectiveness of the mental map in the comprehension of a dynamic graph series. In this paper, we summarize the experiments conducted on this definition of mental map preservation and provide recommendations to designers and researchers to fully understand when the mental map supports user tasks.
Keywords: Dynamic graph drawing; Information visualization; Formal experiments; Mental map
Ecological interface design and sensor noise BIBAKFull-Text 1056-1068
  Olivier St-Cyr; Greg A. Jamieson; Kim J. Vicente
This paper investigates the effects of the presence and magnitude of sensor noise on operators' performance and control stability when they use an Ecological Interface Design (EID) interface and a non-EID interface. Sensor noise was gradually increased in selected low-level physical sensors of DURESS III, a representative thermal-hydraulic process simulation. There are two important findings. First, participants in the EID condition achieved target goals significantly faster across all magnitudes of sensor noise. Second, participants in the EID condition exhibited more stable control; experiencing fewer and shorter oscillations around the target goals. This is the first study to empirically investigate the impact of the presence and magnitude of sensor noise on the robustness and effectiveness of an EID interface. These findings are important if EID is to be applied in industrial settings.
Keywords: Sensor noise; Ecological interface design; Display design; Human-computer interaction; Instrumentation
Who but not where: The effect of social play on immersion in digital games BIBAKFull-Text 1069-1077
  Paul Cairns; Anna L. Cox; Matthew Day; Hayley Martin; Thomas Perryman
The majority of digital games available today offer a variety of multi-player settings including co-located and mediated play between opponents. Immersion, the sense of being "in the game," is one of the key components of the gaming experience but existing literature suggests that social play provides more fun but less immersion. There is however little empirical support for this. This paper therefore addresses the question: how does playing digital games in a social situation alter the sense of immersion felt by the individuals playing? This paper presents three experiments that test the relationship between social setting and immersion. The three experiments aim to manipulate the social setting in which players play, be it against a computer, against a person online or against a co-located person. Overall the three experiments show that players are more immersed when playing against another person rather than playing against a computer but there is no significant difference in immersion whether the other person is online or in the same room. This refutes previous claims about social play reducing immersion and indeed that social play enhances the sense of being in the game where interaction is through the game.
Keywords: Digital games; Immersion; Social play; Social presence; Gaming experience
Large high resolution displays for co-located collaborative sensemaking: Display usage and territoriality BIBAKFull-Text 1078-1088
  Lauren Bradel; Alex Endert; Kristen Koch; Christopher Andrews; Chris North
From an exploratory user study using a fictional textual intelligence analysis task on a large, high-resolution vertical display, we investigated how pairs of users interact with the display to construct spatial schemas and externalize information, as well as how they establish shared and private territories. We investigated users' space management strategies depending on the design philosophy of the user interface (visualization- or document-centric). We classified the types of territorial behavior exhibited in terms of how the users interacted with information on the display (integrated or independent workspaces). Next, we examined how territorial behavior impacted the common ground between the pairs of users. Finally, we offer design suggestions for building future co-located collaborative visual analytics tools for use on large, high-resolution vertical displays.
Keywords: Large high-resolution displays; Co-located collaborative sensemaking; Visual analytics; Territoriality

IJHCS 2013-12 Volume 71 Issue 12

The impact of task framing and viewing timing on user website perceptions and viewing behavior BIBAKFull-Text 1089-1102
  Dianne Cyr; Milena Head
It is generally recognized that online shopping has both utilitarian as well as hedonic components. The primary focus of this investigation is to examine task framing (either utilitarian or hedonic) and length of viewing time (unlimited or 5 s) as conditions that influence user website perceptions and viewing behavior. Whether a task is framed as either hedonic or utilitarian received limited support. However, viewing time does make a difference and unconstrained viewing versus 5 s of viewing time results in higher levels of perceived involvement, enjoyment, trust, and effectiveness. In addition, eye-tracking results indicate that users tend to focus more on hedonic zones versus utilitarian zones (i.e. exhibit higher number of fixations and longer viewing times). Interview data provide additional support and insights. In sum, these findings contribute to understanding the complex and dynamic perceptions of online shoppers.
Keywords: Hedonic; Utilitarian; Task framing; Website viewing time; Eye-tracking
Touching annotations: A visual metaphor for navigation of annotation in digital documents BIBAKFull-Text 1103-1111
  C. P. Bowers; C. Creed; B. R. Cowan; R. Beale
Direct touch manipulation interactions with technology are now commonplace and significant interest is building around their use in the culture and heritage domain. Such interactions can give people the opportunity to explore materials and artefacts in ways that would otherwise be unavailable. These are often heavily annotated and can be linked to a large array of related digital content, thus enriching the experience for the user. Research has addressed issues of how to present digital documents and their related annotations but at present it is unclear what the optimal interaction approach to navigating these annotations in a touch display context might be.
   In this paper we investigate the role of two alternative approaches to support the navigation of annotations in digitised documents in the context of a touch interface. Through a control study we demonstrate that, whilst the navigation paradigm displays a significant interaction with the type of annotations task performed, there is no discernible advantage of using a natural visual metaphor for annotation in this context. This suggests that design of digital document annotation navigation tools should account for the context and navigation tasks being considered.
Keywords: Document navigation; Touch interaction; Affordance; Interaction techniques; User study
Development of scales for the measurement of principles of design BIBAKFull-Text 1112-1123
  Julian Lin
Principles of design have been widely applied by practitioners such as photographers, artists, architects, designers, and others for many years. This paper examines whether the principles advocated by practitioners systematically and reliably influence perceived aesthetics and perceived ease of use constructs that are important for the evaluation of websites. To examine these relationships, the paper offers an operational definition, develops and validates a measurement tool for assessing the principles. To provide a comprehensive and broad definition of the principles, over 20 books written by practitioners were reviewed and more than 100 questionnaire items were extracted. These items were further refined through two rounds of content analysis using emergent and a priori coding with 10 judges and 2 experts. The remaining items from the two rounds of coding were examined using surveys. Exploratory and confirmatory factor analyses were performed. The results show that the items under 6 constructs have adequate convergent and discriminant validity. Lastly, a field study testing effects of the principles on perceived ease of use and aesthetics was conducted. The results show that principles of design predict perceived ease of use better than perceived aesthetics. Implications for practice and research are discussed.
Keywords: Principle; Visual design; Measurement; Instrument; Survey
Editorial BIBFull-Text 1124-1125
  Asimina Vasalou; Tristan Henderson; Adam Joinson
A reflexive analysis of 'context' in privacy research: Two case studies in HIV care BIBAKFull-Text 1126-1132
  Fadhila Mazanderani; Chrysanthi Papoutsi; Ian Brown
Privacy is a much discussed and politically charged topic in contemporary healthcare. Yet, studying the actual privacy practices of healthcare professionals and patients remains extremely challenging. In this paper we reflect on our experiences using qualitative methods in two projects on HIV care, the first researching internet use by a particular group of patients, and the second looking at issues of information technology integration in hospitals. Our aim in doing so is to highlight some of the opportunities and challenges involved in including an explicit focus on 'context' in qualitative privacy research in healthcare. We suggest that adopting a more reflexive approach to the way methods are used in relation to 'context' in privacy-related HCI research provides opportunities for understanding how different 'privacy contexts' are enacted in and through our research practices in different environments.
Keywords: Privacy; HIV; Methods; Context; Reflexivity
Guide to measuring privacy concern: Review of survey and observational instruments BIBAKFull-Text 1133-1143
  Sören Preibusch
The debate about online privacy gives testimony of Web users' concerns. Privacy concerns make consumers adopt data protection features, guide their appreciation for existing features, and can steer their consumption choices amongst competing businesses. However, approaches to measure privacy concern are fragmented and often ad-hoc, at the detriment of reliable results.
   The need for measurement instruments for privacy concern is twofold. First, attitudes and opinions about data protection cannot be established and compared without reliable mechanisms. Second, behavioural studies, notably in technology acceptance and the behavioural economics of privacy require measures for concern as a moderating factor.
   In its first part, this paper provides a comprehensive review of existing survey instruments for measuring privacy concerns. The second part focuses on revealed preferences that can be used for opportunistically measuring privacy concerns in the wild or for scale validation. Recommendations for scale selection and reuse are provided.
Keywords: Privacy concern; Willingness to disclose; Information privacy; Measurement; Scale development; Scale reuse; Experiments and questionnaires; Observational methods; Survey research
Dimensionality of information disclosure behavior BIBAKFull-Text 1144-1162
  Bart P. Knijnenburg; Alfred Kobsa; Hongxia Jin
In studies of people's privacy behavior, the extent of disclosure of personal information is typically measured as a summed total or a ratio of disclosure. In this paper, we evaluate three information disclosure datasets using a six-step statistical analysis, and show that people's disclosure behaviors are rather multidimensional: participants' disclosure of personal information breaks down into a number of distinct factors. Moreover, people can be classified along these dimensions into groups with different "disclosure styles'. This difference is not merely in degree, but rather also in kind: one group may for instance disclose location-related but not interest-related items, whereas another group may behave exactly the other way around. We also found other significant differences between these groups, in terms of privacy attitudes, behaviors, and demographic characteristics. These might for instance allow an online system to classify its users into their respective privacy group, and to adapt its privacy practices to the disclosure style of this group. We discuss how our results provide relevant insights for a more user-centric approach to privacy and, more generally, advance our understanding of online privacy behavior.
Keywords: Privacy behavior; Privacy attitude; Information disclosure; Measurement; Factor analysis; Latent class analysis; Structural equation modeling
Information disclosure on mobile devices: Re-examining privacy calculus with actual user behavior BIBAKFull-Text 1163-1173
  Mark J. Keith; Samuel C. Thompson; Joanne Hale; Paul Benjamin Lowry; Chapman Greer
The use of mobile applications continues to experience exponential growth. Using mobile apps typically requires the disclosure of location data, which often accompanies requests for various other forms of private information. Existing research on information privacy has implied that consumers are willing to accept privacy risks for relatively negligible benefits, and the offerings of mobile apps based on location-based services (LBS) appear to be no different. However, until now, researchers have struggled to replicate realistic privacy risks within experimental methodologies designed to manipulate independent variables. Moreover, minimal research has successfully captured actual information disclosure over mobile devices based on realistic risk perceptions. The purpose of this study is to propose and test a more realistic experimental methodology designed to replicate real perceptions of privacy risk and capture the effects of actual information disclosure decisions. As with prior research, this study employs a theoretical lens based on privacy calculus. However, we draw more detailed and valid conclusions due to our use of improved methodological rigor. We report the results of a controlled experiment involving consumers (n=1025) in a range of ages, levels of education, and employment experience. Based on our methodology, we find that only a weak, albeit significant, relationship exists between information disclosure intentions and actual disclosure. In addition, this relationship is heavily moderated by the consumer practice of disclosing false data. We conclude by discussing the contributions of our methodology and the possibilities for extending it for additional mobile privacy research.
Keywords: Information privacy; Information disclosure; Location data; Mobile devices; Smartphone; Experimental methodology; Privacy calculus