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IJHCS Tables of Contents: 60616263646566676869707172

International Journal of Human-Computer Studies 70

Editors:Enrico Motta; Susan Wiedenbeck
Publisher:Elsevier Science Publishers
Standard No:ISSN 0020-7373; TA 167 A1 I5
Links:Table of Contents
  1. IJHCS 2012-01 Volume 70 Issue 1
  2. IJHCS 2012-02 Volume 70 Issue 2
  3. IJHCS 2012-03 Volume 70 Issue 3
  4. IJHCS 2012-04 Volume 70 Issue 4
  5. IJHCS 2012-05 Volume 70 Issue 5
  6. IJHCS 2012-06 Volume 70 Issue 6
  7. IJHCS 2012-07 Volume 70 Issue 7
  8. IJHCS 2012-08 Volume 70 Issue 8
  9. IJHCS 2012-09 Volume 70 Issue 9
  10. IJHCS 2012-10 Volume 70 Issue 10
  11. IJHCS 2012-11 Volume 70 Issue 11
  12. IJHCS 2012-12 Volume 70 Issue 12

IJHCS 2012-01 Volume 70 Issue 1

To buy or not to buy: Influence of seller photos and reputation on buyer trust and purchase behavior BIBAKFull-Text 1-13
  Gary Bente; Odile Baptist; Haug Leuschner
Reputation scores and seller photos are regarded as two types of signals promoting trust in e-commerce. Little is known about their differential impact when co-occurring in online transactions. Using a computer-mediated trust game, the current study combined three photo conditions (trustworthy, untrustworthy and no seller photo) with three reputation conditions (positive, negative and no seller reputation) in a 3x3 within-subject design. Buyers' ratings of trust and number of purchases served as dependent variables. Significant main effects were found for reputation scores and photos on both dependent variables and there was no interaction effect. Trustworthy photos and positive reputation contributed towards buyers' trust and higher purchase rates. Surprisingly, neither untrustworthy photos nor negative reputation performed worse than missing information. On the contrary, completely missing information (no reputation, no photo) led to distrust and differed significantly from completely negative information (low reputation, untrustworthy photo), which resulted in a neutral trust level. Overall, the data suggest that not only does positive information increase trust, but mere uncertainty reduction regarding a seller can also contribute towards trust in online transactions.
Keywords: e-Commerce; Trust; Reputation; Seller photos; Self-disclosure; Uncertainty reduction; Trust game
Adaptive browsing: Sensitivity to time pressure and task difficulty BIBAKFull-Text 14-25
  Susan C. Wilkinson; Will Reader; Stephen J. Payne
Two experiments explored how learners allocate limited time across a set of relevant on-line texts, in order to determine the extent to which time allocation is sensitive to local task demands. The first experiment supported the idea that learners will spend more of their time reading easier texts when reading time is more limited; the second experiment showed that readers shift preference towards harder texts when their learning goals are more demanding. These phenomena evince an impressive capability of readers. Further, the experiments reveal that the most common method of time allocation is a version of satisficing (Reader and Payne, 2007) in which preference for texts emerges without any explicit comparison of the texts (the longest time spent reading each text is on the first time that text is encountered). These experiments therefore offer further empirical confirmation for a method of time allocation that relies on monitoring on-line texts as they are read, and which is sensitive to learning goals, available time and text difficulty.
Keywords: Browsing; Information foraging; Satisficing; Sampling
How do usability professionals construe usability? BIBAKFull-Text 26-42
  Morten Hertzum; Torkil Clemmensen
Usability professionals have attained a specialist role in systems-development projects. This study analyses usability professionals' operational understanding of usability by eliciting the constructs they employ in their thinking about system use. We approach usability broadly and without a priori distinguishing it from user experience. On the basis of repertory-grid interviews with 24 Chinese, Danish, and Indian usability professionals we find that they make use of more utilitarian than experiential, i.e. user-experience related, constructs. This indicates that goal-related performance is central to their thinking about usability, whereas they have less elaborate sets of experiential constructs. The usability professionals mostly construe usability at an individual level, rather than at organizational and environmental levels. The few exceptions include effectiveness constructs, which are evenly spread across all three levels, and relational constructs, which are phrased in terms of social context. Considerations about users' cognitive activities appear more central to the usability professionals than conventional human-factors knowledge about users' sensorial abilities. The usability professionals' constructs, particularly their experiential constructs, go considerably beyond ISO 9241 usability, indicating a discrepancy between this definition of usability and the thinking of the professionals concerned with delivering usability. Finally, usability is construed rather similarly across the three nationalities of usability professionals.
Keywords: Usability Professional; Usability; User experience; Quality in use; Repertory-grid interview; Personal construct
Workarounds in the use of IS in healthcare: A case study of an electronic medication administration system BIBAKFull-Text 43-65
  Zhenbin Yang; Boon-Yuen Ng; Atreyi Kankanhalli; James Wei Luen Yip
Healthcare information systems such as an Electronic Medication Administration System (EMAS) have the potential to enhance productivity, lower costs, and reduce medication errors. However, various issues have arisen from the use of these systems. A key issue relates to workarounds as a result of a misfit between the new information system (IS) implementation and existing work processes. However, there is a lack of understanding and studies on healthcare IS workarounds and their outcomes. This paper applies the theoretical perspectives of accommodation to misfit and IS evolution to understand the phenomenon through an in-depth case study of an EMAS implemented in a large public hospital. Based on the findings, it develops a process framework to explain how the benefits, issues, and workarounds inter-relate and determine the impacts of the system. The findings have implications for research and practice on workarounds in the use of healthcare IS.
Keywords: Healthcare IS; Workarounds; Issues; Benefits; Augmenting; Fitting; Electronic Medication Administration
A review of locative media, mobile and embodied spatial interaction BIBKFull-Text 66-71
  Mark Bilandzic; Marcus Foth
Keywords: Urban informatics; Locative media; Mobile spatial interaction; Embodied interaction; Mobile web 2.0; Context; Awareness; Mobile interaction
Aesthetic images modulate emotional responses to reading news messages on a small screen: A psychophysiological investigation BIBAKFull-Text 72-87
  Jari Kätsyri; Niklas Ravaja; Mikko Salminen
Abstract pictures, such as artistic drawings, may evoke subtle emotions in their observers via aesthetic experiences. We examined among 44 participants the emotional responses as measured by facial electromyography (EMG) to aesthetic background images that varied on the emotional valence (unpleasant to pleasant) and arousal (calming to exciting) dimensions and were presented both separately and as background images for news messages. Effects of image arousal on free recall of news messages were also examined. A priori pleasant compared to unpleasant images were associated with higher orbicularis oculi EMG responses, both when presented alone and when presented as news message backgrounds. Analyses based on the participants' subjective pleasantness ratings also showed greater corrugator supercilii EMG activity for unpleasant compared to pleasant images. High-arousal as compared to low-arousal images improved recall for the superimposed news messages. In contrast, recall was not affected by a priori image valence or subjective pleasantness ratings. The results demonstrate that abstract images can be used to evoke emotional responses in the viewers that persist even when unrelated messages are superimposed on them. Similarly, high-arousal images can be used to enhance memory for superimposed textual messages.
Keywords: Psychophysiology; Emotion; Media; Aesthetics; User interfaces
Spatial proximity is more than just a distance measure BIBAKFull-Text 88-106
  Jane Brennan; Eric Martin
In order to design computer systems that are intuitive to use, the way humans reason about their "real world' surroundings needs to be taken into consideration. Geographic Information Systems (GIS) focus on spatial reasoning. Over the last decades, many advances have been made in GIS interfaces and functionality; however the concept of proximity or nearness, which is essential in many forms of human reasoning, is still being addressed insufficiently.
   This paper provides a thorough and comprehensive synthesis of the disparate literature that pertains to the subject of proximity. It offers insights into why existing methods for reasoning with proximity work, or do not work, and analyses their strengths and weaknesses. Finally, the paper provides the derivation of new proximity measures, and their evaluation, backed by experiments and reflections. New measures are formally described in a unifying and compelling framework. This framework acknowledges that while distance is one factor that influences proximity perception, proximity is much more than just a distance measure.
Keywords: Spatial cognition; Spatial proximity; Nearness; Knowledge representation; Spatial reasoning

IJHCS 2012-02 Volume 70 Issue 2

A new look at software piracy: Soft lifting primes an inauthentic sense of self, prompting further unethical behavior BIBAKFull-Text 107-115
  Wen-Bin Chiou; Peng-Hui Wan; Chin-Sheng Wan
Soft lifting refers to the process whereby a legally licensed software program is installed or copied in violation of its licensing agreement. Previous research on this pervasive kind of unethical computer use has mainly focused on the determinants of this unethical act, which are rooted in personal, economic, technological, cultural, socio-political, or legal domains. However, little is known about the symbolic power that soft lifting has on the sense of self. Based on recent advances in behavioral priming, we hypothesized that soft lifting can influence the signals one sends to oneself; more specifically, soft lifting may prime individuals to experience an inauthentic sense of self, which, in turn, prompts further unethical behavior. In Study 1, we showed that participants, primed with the memory of a recent soft lifting experience, cheated more than participants recalling a recent experience of purchasing authentic software or than control participants. Moreover, feelings of inauthenticity mediated the priming effect of soft lifting on dishonest behavior. In Study 2, participants primed with soft lifting showed a greater willingness to purchase a wide range of counterfeit products over authentic products. Besides those antecedents or correlates of soft lifting already identified in the literature, educators should pay more attention to the negative impact of soft lifting on the self-images of users, which may go beyond computer-related behaviors. Priming may provide a new direction for HCI researchers to examine the impact of computer-use-related factors on users' perceptions, motivations, and behaviors.
Keywords: Behavioral priming; Computer ethics; Counterfeit products; Soft lifting
Human-automated path planning optimization and decision support BIBAKFull-Text 116-128
  M. L. Cummings; J. J. Marquez; N. Roy
Path planning is a problem encountered in multiple domains, including unmanned vehicle control, air traffic control, and future exploration missions to the Moon and Mars. Due to the voluminous and complex nature of the data, path planning in such demanding environments requires the use of automated planners. In order to better understand how to support human operators in the task of path planning with computer aids, an experiment was conducted with a prototype path planner under various conditions to assess the effect on operator performance. Participants were asked to create and optimize paths based on increasingly complex path cost functions, using different map visualizations including a novel visualization based on a numerical potential field algorithm. They also planned paths under degraded automation conditions. Participants exhibited two types of analysis strategies, which were global path regeneration and local sensitivity analysis. No main effect due to visualization was detected, but results indicated that the type of optimizing cost function affected performance, as measured by metabolic costs, sun position, path distance, and task time. Unexpectedly, participants were able to better optimize more complex cost functions as compared to a simple time-based cost function.
Keywords: Human -- automation interaction; Path planning; Decision support systems
Facets of simplicity for the smartphone interface: A structural model BIBAKFull-Text 129-142
  Junho H. Choi; Hye-Jin Lee
Motivated by the need to develop an integrated measure of simplicity perception for a smartphone user interface, our research incorporated visual aesthetics, information design, and task complexity into an extended construct of simplicity. Drawn from three distinct domains of human -- computer interaction design and related areas, the new development of a simplicity construct and measurement scales were then validated. The final measurement model consisted of six components: reduction, organization, component complexity, coordinative complexity, dynamic complexity, and visual aesthetics. The following phase aimed at verifying the relationship between simplicity perception of the interface and evaluations of user satisfaction. The hypothesis was accepted that user satisfaction was positively affected by simplicity perception and that the relationship between the two constructs was very strong. The findings imply that a simplified interface design of the task performance, information hierarchy, and visual display attributes contributes to positive satisfaction evaluations when users interact with their smartphone as they engage in communication, information search, and entertainment activities.
Keywords: Smartphone; Simplicity; Satisfaction; Visual aesthetics; Information design; Task complexity
Expertise-dependent visual attention strategies develop over time during debugging with multiple code representations BIBAKFull-Text 143-155
  Roman Bednarik
In modern multi-representational environments, software developers need to coordinate various information sources to effectively perform maintenance tasks. Although visual attention is an important skill in software development, our current understanding of the role of visual attention in the coordination of representations during maintenance tasks is minimal. Therefore, we applied eye-tracking to capture visual attention strategies and construct a detailed account of visual attention during debugging. Two groups of programmers with two distinct levels of experience debugged a program with the help of multiple representations. The proportion of time spent looking at each representation, the frequency of switching attention between visualrepresentations and the type of switch were investigated during consecutive phases of debugging. We found repetitive patterns in visual strategies that were associated with less expertise and lower performance. Novice developers made use of both the code and graphical representations while frequently switching between them. More experienced participants expended more efforts integrating the available information and primarily concentrated on systematically relating the code to the output. Our results informed us about the differences in program debugging strategies from a fine-grain, temporal perspective and have implications for the design of future development environments.
Keywords: Expertise in programming; Visual attention; Program debugging
Juggling on a high wire: Multitasking effects on performance BIBAKFull-Text 156-168
  Rachel F. Adler; Raquel Benbunan-Fich
In this study, we develop a theoretical model that predicts an inverted-U relationship between multitasking and performance. The model is tested with a controlled experiment using a custom-developed application. Participants were randomly assigned to either a control condition, where they had to perform tasks in sequence, or an experimental condition, where they could discretionarily switch tasks by clicking on tabs. Our results show an inverted-U pattern for performance efficiency (productivity) and a decreasing line for performance effectiveness (accuracy). The results of this study indicate that the nature of the relation between multitasking and performance depends upon the metric used. If performance is measured with productivity, different multitasking levels are associated with an inverted-U curve where medium multitaskers perform significantly better than both high and low multitaskers. However, if performance is measured with accuracy of results, the relation is a downward slopping line, in which increased levels of multitasking lead to a significant loss in accuracy. Metaphorically speaking, juggling multiple tasks is much more difficult while balancing on a high wire, where performance mishaps can have serious consequences.
Keywords: Memory for goals; Multitasking; Task switching; Performance
Computer mediated imaginative storytelling in children with autism BIBAKFull-Text 169-178
  Gayle Dillon; Jean Underwood
The imaginative abilities of children on the autistic spectrum are reportedly impaired compared to typically developing children. This study explored computer mediated story construction in children with autism and typically developing peers. The purpose was to explore expressive writing ability, as a measure of imagination. Ten pairs of individually matched children (one typically developing and one child on the autistic spectrum) aged between seven and nine created reality and fantasy based stories using Bubble Dialogue software. The study provided a brief starting point for the stories, relying on the imaginative capabilities of the children to develop the stories beyond the story opening. The study contributes to the literature as an alternative to paper based studies of imagination given the known appeal of technology to most children, particularly children on the autistic spectrum (Gal et al., 2005). This study found that the children with autism were as able as the typically developing children to engage with the task, although qualitative differences in their responses were recorded.
Keywords: Autism; Computer mediated storytelling; User experience

IJHCS 2012-03 Volume 70 Issue 3

Tailored presentation of dynamic web content for audio browsers BIBAKFull-Text 179-196
  Andy Brown; Caroline Jay; Simon Harper
Understanding the content of a Web page and navigating within and between pages are crucial tasks for any Web user. To those who are accessing pages through non-visual means, such as screen readers, the challenges offered by these tasks are not easily overcome, even when pages are unchanging documents. The advent of 'Web 2.0' and Web applications, however, means that documents often are not static, but update, either automatically or due to user interaction. This development poses a difficult question for screen reader designers: how should users be notified of page changes? In this article we introduce rules for presenting such updates, derived from studies of how sighted users interact with them. An implementation of the rules has been evaluated, showing that users who were blind or visually impaired found updates easier to deal with than the relatively quiet way in which current screen readers often present them.
Keywords: Web 2.0; AJAX; Visual disability; Eye-tracking
Combining ethnography and object-orientation for mobile interaction design: Contextual richness and abstract models BIBAKFull-Text 197-217
  Jesper Kjeldskov; Jan Stage
There has been a lot of interest in ethnography within human -- computer interaction over the last two decades, and its relevance within systems development is today beyond question. However, one of the challenges reported is that ethnography generates findings and knowledge with such contextual richness that it can be hard to transfer into system design. In the light of recent years' push for the use of ethnography within the area of mobile human -- computer interaction, this challenge has resurfaced and is of renewed importance to the research field. In this article we describe an interdisciplinary combination of ethnography with a structured software engineering method supporting the transition from collected data to design and implementation. We explore this combination through two case studies of mobile system development for supporting distributed work activities within industrial process control. We show that when developing mobile systems ethnographic data is a highly valuable source of input for developing object-oriented models by providing contextual richness, and that in turn, objected-oriented analysis is a highly valuable method for working with ethnographic field data in systems development by supporting the creation of abstract models. Combining the two, we have a method where ethnographic field studies inform core system design.
Keywords: Mobile interaction design; Ethnography; Object-oriented analysis; System development; Mobile work; Distributed collaboration
Understanding performance in touch selections: Tap, drag and radial pointing drag with finger, stylus and mouse BIBAKFull-Text 218-233
  A. Cockburn; D. Ahlström; C. Gutwin
Touch-based interaction with computing devices is becoming more and more common. In order to design for this setting, it is critical to understand the basic human factors of touch interactions such as tapping and dragging; however, there is relatively little empirical research in this area, particularly for touch-based dragging.
   To provide foundational knowledge in this area, and to help designers understand the human factors of touch-based interactions, we conducted an experiment using three input devices (the finger, a stylus, and a mouse as a performance baseline) and three different pointing activities. The pointing activities were bidirectional tapping, one-dimensional dragging, and radial dragging (pointing to items arranged in a circle around the cursor). Tapping activities represent the elemental target selection method and are analysed as a performance baseline. Dragging is also a basic interaction method and understanding its performance is important for touch-based interfaces because it involves relatively high contact friction. Radial dragging is also important for touch-based systems as this technique is claimed to be well suited to direct input yet radial selections normally involve the relatively unstudied dragging action, and there have been few studies of the interaction mechanics of radial dragging. Performance models of tap, drag, and radial dragging are analysed.
   For tapping tasks, we confirm prior results showing finger pointing to be faster than the stylus/mouse but inaccurate, particularly with small targets. In dragging tasks, we also confirm that finger input is slower than the mouse and stylus, probably due to the relatively high surface friction. Dragging errors were low in all conditions. As expected, performance conformed to Fitts' Law.
   Our results for radial dragging are new, showing that errors, task time and movement distance are all linearly correlated with number of items available. We demonstrate that this performance is modelled by the Steering Law (where the tunnel width increases with movement distance) rather than Fitts' Law. Other radial dragging results showed that the stylus is fastest, followed by the mouse and finger, but that the stylus has the highest error rate of the three devices. Finger selections in the North-West direction were particularly slow and error prone, possibly due to a tendency for the finger to stick -- slip when dragging in that direction.
Keywords: Touch interaction; Dragging; Radial menus
An electromyographic study of a laser pointer-style device vs. mouse and keyboard in an object arrangement task on a large screen BIBAKFull-Text 234-255
  Luca Chittaro; Riccardo Sioni
A large body of HCI research focuses on devices and techniques to interact with applications in more natural ways, such as gestures or direct pointing with fingers or hands. In particular, recent years have seen a growing interest in laser pointer-style (LPS) interaction, which allows users to point directly at the screen from a distance through a device handled like a common laser pointer. Several LPS techniques have been evaluated in the literature, usually focusing on users' performance and subjective ratings, but not on the effects of these techniques on the musculoskeletal system. One cannot rule out that "natural' interaction techniques, although found attractive by users, require movements that might increase likelihood of musculoskeletal disorders (MSDs) with respect to traditional keyboard and mouse. Our study investigates the physiological effects of a LPS interaction technique (based on the Wii Remote) compared to a mouse and keyboard setup, used in a sitting and a standing posture. The task (object arrangement) is representative of user actions repeatedly carried out with 3D applications. The obtained results show that the LPS interaction caused more muscle exertion than mouse and keyboard. Posture played also a significant role. The results highlight the importance of extending current studies of novel interaction techniques with thorough electromyographic (EMG) analyses.
Keywords: Wii Remote; Laser pointer; Muscle activity; EMG; 3D environments; Large screen; Object arrangement; Ray casting

IJHCS 2012-04 Volume 70 Issue 4

Auditory feedback in haptic collaborative interfaces BIBAKFull-Text 257-270
  Ying Ying Huang; Jonas Moll; Eva-Lotta Sallnäs; Yngve Sundblad
The combined effect of haptic and auditory feedback in shared interfaces on the cooperation between visually impaired and sighted persons is under-investigated. A central challenge for cooperating group members lies in obtaining a common understanding of the elements of the workspace and maintaining awareness of the other members' actions, as well as one's own, during the group work process. The aim of the experimental study presented here was to investigate if adding audio cues in a haptic and visual interface makes collaboration between a sighted and a blindfolded person more efficient. Results showed that task performance was significantly faster in the audio, haptic and visual feedback condition compared to the haptic and visual feedback condition. One special focus was also to study how participants utilize the auditory and haptic force feedback in order to obtain a common understanding of the workspace and to maintain an awareness of the group members' actions. Results from a qualitative analysis showed that the auditory and haptic feedback was used in a number of important ways to support the group members' action awareness and in the participants' grounding process.
Keywords: Haptic; Force feedback; Virtual environments; Multimodal interface; Collaboration; Awareness; Common ground
Synthesizing mood-affected signed messages: Modifications to the parametric synthesis BIBAKFull-Text 271-286
  Fernando López-Colino; José Colás
This paper describes the first approach in synthesizing mood-affected signed contents. The research focuses on the modifications applied to a parametric sign language synthesizer (based on phonetic descriptions of the signs). We propose some modifications that will allow for the synthesis of different perceived frames of mind within synthetic signed messages. Three of these proposals focus on modifications to three different signs' phonologic parameters (the hand shape, the movement and the non-hand parameter). The other two proposals focus on the temporal aspect of the synthesis (sign speed and transition duration) and the representation of muscular tension through inverse kinematics procedures. These resulting variations have been evaluated by Spanish deaf signers, who have concluded that our system can generate the same signed message with three different frames of mind, which are correctly identified by Spanish Sign Language signers.
Keywords: Sign language synthesis; Frame of mind synthesis; Graphical interface; Deaf people
Design and comparative evaluation of Smoothed Pointing: A velocity-oriented remote pointing enhancement technique BIBAKFull-Text 287-300
  L. Gallo; A. Minutolo
The increasing use of remote pointing devices in various application domains is fostering the adoption of pointing enhancement techniques which are aimed at counterbalancing the shortcomings of desk-free interaction. This paper describes the strengths and weaknesses of existing methods for ray pointing facilitation, and presents a refinement of Smoothed Pointing, an auto-calibrating velocity-oriented precision enhancing technique. Furthermore, the paper discusses the results of a user study aimed at empirically investigating how velocity-oriented approaches perform in target acquisition and in trajectory-based interaction tasks, considering both laser-style and image -- plane pointing modalities. The experiments, carried out in a low precision scenario in which a Wiimote was used both as a wand and a tracking system, show that Smoothed Pointing allows a significant decrease in the error rate and achieves the highest values of throughput in trajectory-based tasks. The results also indicate that the effectiveness of precision enhancing techniques is significantly affected by the pointing modality and the type of pointing task.
Keywords: Ray pointing facilitation; Smoothed Pointing; Velocity-oriented approach; User study; Wiimote
A crowdsourcing method to develop virtual human conversational agents BIBAKFull-Text 301-319
  Brent Rossen; Benjamin Lok
Educators in medicine, psychology, and the military want to provide their students with interpersonal skills practice. Virtual humans offer structured learning of interview skills, can facilitate learning about unusual conditions, and are always available. However, the creation of virtual humans with the ability to understand and respond to natural language requires costly engineering by conversation knowledge engineers (generally computer scientists), and incurs logistical cost for acquiring domain knowledge from domain experts (educators). We address these problems using a novel crowdsourcing method entitled Human-centered Distributed Conversational Modeling. This method facilitates collaborative development of virtual humans by two groups of end-users: domain experts (educators) and domain novices (students). We implemented this method in a web-based authoring tool called Virtual People Factory. Using Virtual People Factory, medical and pharmacy educators are now creating natural language virtual patient interactions on their own. This article presents the theoretical background for Human-centered Distributed Conversational Modeling, the implementation of the Virtual People Factory authoring tool, and five case studies showing that Human-centered Distributed Conversational Modeling has addressed the logistical cost for acquiring knowledge.
Keywords: Virtual humans; Agents and intelligent systems; Human-centered computing; Distributed knowledge acquisition; End-user programming

IJHCS 2012-05 Volume 70 Issue 5

Evaluation methods and strategies for the interactive use of classifiers BIBAKFull-Text 321-331
  Silvia Acid; Luis M. de Campos; Moisés Fernández
We consider the scenario in which an automatic classifier (previously built) is available. It is used to classify new instances but, in some cases, the classifier may request the intervention of a human (the oracle), who gives it the correct class. In this scenario, first it is necessary to study how the performance of the system should be evaluated, as it cannot be based solely on the predictive accuracy obtained by the classifier but it should also take into account the cost of the human intervention; second, studying the concrete circumstances under which the classifier decides to query the oracle is also important. In this paper we study these two questions and include also an experimental evaluation of the different proposed alternatives.
Keywords: Interactivity; Classification; Uncertainty sampling; Evaluation models
Time use behavior in single and time-sharing tasks BIBAKFull-Text 332-345
  Yan Luximon; Ravindra S. Goonetilleke
Human errors in aviation, process plants and other critical industries can result in dire consequences and hence it is essential to understand the operator behavior and task characteristics in order to improve task performance and safety. The time available and how it is used by the operator are important factors in multi-task situations. Polychrons are people, who favor doing multiple tasks at the same time, while monochrons prefer doing tasks in series. In this study, the strategy, performance and workload of monochrons and polychrons were evaluated in a single and dual control tasks. The task difficulty and multiple task priority were independent variables. Results indicated that polychrons switched between two tasks more than monochrons and achieved better performance when the tasks were equally important and difficult. When the priority between the tasks was different, monochrons changed their emphasis to the more important task even though polychrons did not change their strategy as dramatically as the monochrons. In addition, monochrons indicated significantly higher workload and difficulty than polychrons. Results of this study can be important for the development of training programs of personnel involved in time-critical operations.
Keywords: Complex control; Hill-climbing; Monochron/polychron; Time use; Control strategy; Performance; Task characteristics
User disposition and extent of Web utilization: A trait hierarchy approach BIBAKFull-Text 346-363
  Joshua M. Davis; Mun Y. Yi
As it evolves, the World Wide Web (the Web) increasingly reveals the potential to enhance new aspects of our daily lives. While some take full advantage of the Web's diverse and cutting edge offerings, others choose to limit the extent of their utilization to a small subset of the Web's available functions. Recognizing this variation, a growing body of research investigates the drivers of usage behavior on the Web. Individual differences, namely broad personality and IT-specific traits, are highlighted within this stream as important predictors of Web use. Although substantial progress has been made, an important issue still facing trait research in this area is the absence of a theory-grounded basis for inter-relating broad personality and IT-specific traits. As a result, the accumulation of extant trait research is characterized by a disjointed assortment of trait constructs lacking clear theoretical linkages with one another. Additionally, while numerous studies have investigated isolated Web usage behaviors, an important outcome that remains under-investigated is the extent of an individual's utilization of the Web overall. Addressing these issues, the current study leverages the hierarchical view of traits to develop a theory-grounded, integrative model of broad personality and IT-specific traits. After developing the hierarchical model, the integrated network of traits is positioned as a direct antecedent of Web utilization and empirically tested via a two-stage field survey of 230 Web users. The results corroborate most of the hypotheses, providing support for the hierarchical view and extending the knowledge base on Web-user behavior. Overall, this study unifies disjointed personality and IT-specific trait constructs and offers theoretical guidance for future studies, introducing a much-needed ground for cumulative tradition within this stream.
Keywords: Trait hierarchy; Web utilization; IT-specific traits; Personality; Individual differences
When do online shoppers appreciate security enhancement efforts? Effects of financial risk and security level on evaluations of customer authentication BIBAKFull-Text 364-376
  Jong-Eun Roselyn Lee; Shailendra Rao; Clifford Nass; Karin Forssell; Jae Min John
As the popularity of online shopping grows, concerns about identity theft and fraud are increasing. While stronger customer authentication procedures may provide greater protection and thus benefit customers and retailers, security is often traded off against convenience. To provide insight into this security-convenience trade-off in customer authentication, we experimentally investigated how levels of authentication security and financial risk factors affect perception and evaluation of authentication systems in two contexts: security questions (Experiment 1) and card security codes (Experiment 2). Experiment 1, which examined the effects of security level and product price as a financial risk factor, showed that authentication procedures based on higher-level security tended to be perceived as significantly less convenient and more frustrating. Interestingly, participants rated the higher-level security system (i.e., asking more demanding challenge questions) as less convenient and more frustrating when the amount involved in the transactions was higher. Experiment 2, which introduced consumer liability for fraudulent activities as an additional financial risk factor, showed that participants gave more positive ratings of the higher-level security system under full liability than under zero liability. Taken together, the present research suggests that patterns of security-convenience trade-offs reflecting consumers' perception and appreciation of authentication technologies may vary depending on the characteristics of financial risk factors involved in the transaction process.
Keywords: Online shopping; Electronic commerce; Online security; Authentication; Security -- convenience trade-off
Gaze tutor: A gaze-reactive intelligent tutoring system BIBAKFull-Text 377-398
  Sidney D'Mello; Andrew Olney; Claire Williams; Patrick Hays
We developed an intelligent tutoring system (ITS) that aims to promote engagement and learning by dynamically detecting and responding to students' boredom and disengagement. The tutor uses a commercial eye tracker to monitor a student's gaze patterns and identify when the student is bored, disengaged, or is zoning out. The tutor then attempts to reengage the student with dialog moves that direct the student to reorient his or her attentional patterns towards the animated pedagogical agent embodying the tutor. We evaluated the efficacy of the gaze-reactive tutor in promoting learning, motivation, and engagement in a controlled experiment where 48 students were tutored on four biology topics with both gaze-reactive and non-gaze-reactive (control condition) versions of the tutor. The results indicated that: (a) gaze-sensitive dialogs were successful in dynamically reorienting students' attentional patterns to the important areas of the interface, (b) gaze-reactivity was effective in promoting learning gains for questions that required deep reasoning, (c) gaze-reactivity had minimal impact on students' state motivation and on self-reported engagement, and (d) individual differences in scholastic aptitude moderated the impact of gaze-reactivity on overall learning gains. We discuss the implications of our findings, limitations, future work, and consider the possibility of using gaze-reactive ITSs in classrooms.
Keywords: Affective computing; Affect-sensitive ITS; Boredom; Disengagement; Eye tracking; Gaze-sensitive dialogs; Intelligent tutoring systems (ITSs); Zoning out

IJHCS 2012-06 Volume 70 Issue 6

Visual momentum redux BIBAKFull-Text 399-414
  Kevin B. Bennett; John M. Flach
Over 25 years ago Woods (1984) introduced the concept of visual momentum: the extent to which an interface supports a practitioner in transitioning between various information-seeking activities that are required for understanding and exploring work domains. Increasing visual momentum requires the consideration of a range of "cognitive couplings' that span all levels of the interface: between multiple screens, within individual screens, and within a display on a screen. Although the concept has been well received, we believe that its potential to improve the quality of human computer interaction may be under-appreciated. Our purpose in this review is to provide a better understanding of visual momentum: to provide concrete and diverse examples of its successful application, to review empirical findings, to refine and expand the original design techniques that were proposed, and to integrate diverse terms that appear across different research communities.
Keywords: Visual momentum; Cognitive systems engineering; Long shot; Focus+context; Overview+detail; Fish eye views; Center surround; Landmarks; Ecological interface design
Rational security: Modelling everyday password use BIBAKFull-Text 415-431
  Geoffrey B. Duggan; Hilary Johnson; Beate Grawemeyer
To inform the design of security policy, task models of password behaviour were constructed for different user groups -- Computer Scientists, Administrative Staff and Students. These models identified internal and external constraints on user behaviour and the goals for password use within each group. Data were drawn from interviews and diaries of password use. Analyses indicated password security positively correlated with the sensitivity of the task, differences in frequency of password use were related to password security and patterns of password reuse were related to knowledge of security. Modelling revealed Computer Scientists viewed information security as part of their tasks and passwords provided a way of completing their work. By contrast, Admin and Student groups viewed passwords as a cost incurred when accessing the primary task. Differences between the models were related to differences in password security and used to suggest six recommendations for security officers to consider when setting password policy.
Keywords: Password; Security; Task modelling; Rationality
An assessment of email and spontaneous dialog visualizations BIBAKFull-Text 432-449
  Marcus A. Butavicius; Michael D. Lee; Brandon M. Pincombe; Louise G. Mullen; Daniel J. Navarro; Kathryn M. Parsons; Agata McCormac
Two experiments were conducted examining the effectiveness of visualizations of unstructured texts. The first experiment presented transcriptions of unrehearsed dialog and the second used emails. Both experiments showed an advantage in overall performance for semantically structured two-dimensional (2D) spatialized layouts, such as multidimensional scaling (MDS), over structured and non-structured list displays. The second experiment also demonstrated that this advantage is not simply due to the 2D nature of the display, but the combination of 2D display and the semantic structure underpinning it. Without this structure, performance fell to that of a Random List of documents. The effect of document type in this study and in Butavicius and Lee's (2007) study on visualizations of news articles may be partly described by a change in bias on a speed-accuracy trade-off. At one extreme, users were accurate but slow in answering questions based on the dialog texts while, at the other extreme, users were fast but relatively inaccurate when responding to queries about emails. Similarly, users could respond accurately using the non-structured list interface; however, this was at the cost of very long response times and was associated with a technique whereby participants navigated by clicking on neighboring document representations. Implications of these findings for real-world applications are discussed.
Keywords: Data visualization; Multidimensional scaling; Isomap; Empirical evaluation; Human -- computer interaction; Email; Spontaneous dialog
Engineering trust alignment: Theory, method and experimentation BIBAKFull-Text 450-473
  Andrew Koster; Marco Schorlemmer; Jordi Sabater-Mir
In open multi-agent systems trust models are an important tool for agents to achieve effective interactions. However, in these kinds of open systems, the agents do not necessarily use the same, or even similar, trust models, leading to semantic differences between trust evaluations in the different agents. Hence, to successfully use communicated trust evaluations, the agents need to align their trust models. We explicate that currently proposed solutions, such as common ontologies or ontology alignment methods, lead to additional problems and propose a novel approach. We show how the trust alignment can be formed by considering the interactions that agents share and describe a mathematical framework to formulate precisely how the interactions support trust evaluations for both agents. We show how this framework can be used in the alignment process and explain how an alignment should be learned. Finally, we demonstrate this alignment process in practice, using a first-order regression algorithm, to learn an alignment and test it in an example scenario.
Keywords: Alignment; Channel theory; Regression; Trust

IJHCS 2012-07 Volume 70 Issue 7

Exploring User Experience (UX) in virtual learning environments BIBFull-Text 475-477
  Panagiotis Zaharias; Brad Mehlenbacher
Evaluating user experience of adaptive digital educational games with Activity Theory BIBAKFull-Text 478-497
  Effie Lai-Chong Law; Xu Sun
Adaptive digital educational games (DEGs) providing players with relevant interventions can enhance gameplay experience. This advance in game design, however, renders the user experience (UX) evaluation of DEGs even more challenging. To tackle this challenge, we developed a four-dimension evaluation framework (i.e., gaming experience, learning experience, adaptivity, and usability) and applied it to an empirical study with a DEG on teaching geography. Mixed-method approaches were adopted to collect data with 16 boys aged 10-11. Specifically, a so-called Dyadic User Experience Tests (DUxT) was employed; participants were paired up to assume different roles during gameplay. Learning efficacy was evaluated with a pre-post intervention measurement using a domain-specific questionnaire. Learning experience, gaming experiences and usability were evaluated with intensive in situ observations and interviews guided by a multidimensional scheme; content analysis of these transcribed audio data was supplemented by video analysis. Effectiveness of adaptivity algorithms was planned to be evaluated with automatic logfiles, which, unfortunately, could not be realised due to some technical problem. Nonetheless, the user-based data could offer some insights into this issue. Furthermore, we attempted to bridge the existing gap in UX research -- the lack of theoretical frameworks in understanding user experience -- by adopting Engeström's (1987) extended framework of Activity Theory (AT) that provides contextual information essential for understanding contradictions and breakdowns observed in the interactions between the game players. The dyadic gameplay setting allows us to explore the issue of group UX. Implications for further applications of the AT framework in the UX research, especially the interplay between evaluation and redesign (i.e., downstream utility of UX evaluation methods), are discussed.
Keywords: User experience; Digital educational game; Adaptivity; Usability; Activity Theory; Contradictions; Breakdowns; Downstream utility
Perceived fit and satisfaction on web learning performance: IS continuance intention and task-technology fit perspectives BIBAKFull-Text 498-507
  Wen-Shan Lin
Virtual learning system (VLS) is an information system that facilitates e-learning have been widely implemented by higher education institutions to support face-to-face teaching and self-managed learning in the virtual learning and education environment (VLE). This is referred to a blended learning instruction. By adopting the VLS, students are expected to enhance learning by getting access to course-related information and having full opportunities to interact with instructors and peers. However, there are mixed findings revealed in the literature with respect to the learning outcomes in adopting VLS. In this study, we argue that the link between the precedents of leading students to continue to use VLSs and their impacts on learning effectiveness and productivity are overlooked in the literature. This paper aims to tackle this question by integrating information system (IS) continuance theory with task-technology fit (TTF) to extend our understandings of the precedents of the intention to continue VLS and their impacts on learning. By doing it, factors of technology-acceptance-to-performance, based on TAM (technology acceptance model) and TTF and post-technology-acceptance, based on expectation -- confirmation theory, models can be included to test in one study. The results reveal that perceived fit and satisfaction are important precedents of the intention to continue VLS and individual performance. Later, a discussion and conclusions are provided. This study sheds light on learning system design as assisted by IS in VLE and can serve as a basis for promoting VLS in assisting learning.
Keywords: Perceived fit; Satisfaction; Continuance intention; Virtual learning system (VLS); Virtual learning and education environment (VLE)
Investigating user experience in Second Life for collaborative learning BIBAKFull-Text 508-525
  Alistair Sutcliffe; Amal Alrayes
Two studies on collaborative learning in Second Life are reported. The first is an ecological study of Second Life used in an undergraduate class, by observation, interviews, and limit surveys. Use of Second Life motivated students with good user experience, although they viewed it as a games technology. Second Life was used to prepare virtual meetings and presentations but not for online discussion, with Blackboard and especially Facebook providing collaborative support. In the second experimental study, the effectiveness and user experience with Second Life and Blackboard were compared, including a face-to-face control condition. There were no performance differences overall, although face-to-face was quicker and was preferred by users, followed by Blackboard and Second Life. Blackboard was perceived to be more usable, whereas Second Life provided a better user experience. Worst performance was indicated by dislike of avatar interaction in Second Life, and poor user experience in Blackboard, whereas better performance was associated with engagement with avatars, and better usability in Blackboard. The results of both studies are reviewed using Salmon's model for online learning, suggesting that Second Life helped motivation and socialisation stages, although integration with other technologies is necessary for knowledge construction. Preliminary guidelines are proposed for configuration and management of Second Life in collaborative learning. The affordances for collaboration in virtual worlds are discussed, with reflections on user experience and functional support provided by Second Life, as an exemplar of a virtual world for collaborative learning support.
Keywords: Collaborative problem solving and learning; User experience; Affordances

IJHCS 2012-08 Volume 70 Issue 8

Distinguishing first-line defaults and second-line conceptualization in reasoning about humans, robots, and computers BIBAKFull-Text 527-534
  Daniel T. Levin; Megan M. Saylor; Simon D. Lynn
In the previous research, we demonstrated that people distinguish between human and nonhuman intelligence by assuming that humans are more likely to engage in intentional goal-directed behaviors than computers or robots. In the present study, we tested whether participants who respond relatively quickly when making predictions about an entity are more or less likely to distinguish between human and nonhuman agents on the dimension of intentionality. Participants responded to a series of five scenarios in which they chose between intentional and nonintentional actions for a human, a computer, and a robot. Results indicated that participants who chose quickly were more likely to distinguish human and nonhuman agents than participants who deliberated more over their responses. We suggest that the short-response time participants were employing a first-line default to distinguish between human intentionality and more mechanical nonhuman behavior, and that the slower, more deliberative participants engaged in deeper second-line reasoning that led them to change their predictions for the behavior of a human agent.
Keywords: Human-robot interaction; Theory of mind
A taxonomy of representation strategies in iconic communication BIBAKFull-Text 535-551
  Carlos Nakamura; Qing Zeng-Treitler
Predicting whether the intended audience will be able to recognize the meaning of an icon or pictograph is not an easy task. Many icon recognition studies have been conducted in the past. However, their findings cannot be generalized to other icons that were not included in the study, which, we argue, is their main limitation. In this paper, we propose a comprehensive taxonomy of icons that is intended to enable the generalization of the findings of recognition studies. To accomplish this, we analyzed a sample of more than eight hundred icons according to three axes: lexical category, semantic category, and representation strategy. Three basic representation strategies were identified: visual similarity; semantic association; and arbitrary convention. These representation strategies are in agreement with the strategies identified in previous taxonomies. However, a greater number of subcategories of these strategies were identified. Our results also indicate that the lexical and semantic attributes of a concept influence the choice of representation strategy.
Keywords: Icon; Pictograph; Pictogram; Iconic communication; Pictorial communication; Taxonomy
Detecting system failures from durations and binary cues BIBAKFull-Text 552-560
  Nir Shahar; Joachim Meyer; Michael Hildebrandt; Vered Rafaely
Durations are often used to judge the status of an invisible process. However, the apparent duration of an interval depends on the actual duration and on other variables, such as the workload during the interval and the person's expectations. An experiment dealt with the use of durations as an information source on the state of an invisible process and the effects of expectations and workload on decisions regarding the process. Eighty-nine participants observed a computerized simulation of a process which could be either intact or faulty, with intact processes ending on average sooner than faulty ones, and they had to indicate whether or not the process is intact and to estimate its duration. A binary cue with either intermediate or no validity indicated whether the process was supposedly intact or not, generating expectations about the duration of the process. Perceived durations and the decisions about the intactness of a process depended on the actual process duration, as well as on the expectations generated by the binary cue. In addition, task workload affected time estimates, but it had no effect on participants' tendency to adhere to cue recommendations or their ability to distinguish between intact and faulty processes. Results show that users' duration-based decisions about the status of a computerized process are affected by internal and external cues. While users can use durations as an information source, they should, whenever possible, be accompanied by additional indicators, lowering the inherent uncertainty in the duration estimation process.
Keywords: Failure detection; Signal detection theory; Time estimation; Apparent duration; Categorization decisions; Decision making
The Immersive Virtual Environment of the digital fulldome: Considerations of relevant psychological processes BIBAKFull-Text 561-575
  Simone Schnall; Craig Hedge; Ruth Weaver
One of the most recent additions to the range of Immersive Virtual Environments has been the digital fulldome. However, not much empirical research has been conducted to explore its potential and benefits over other types of presentation formats. In this review we provide a framework within which to examine the properties of fulldome environments and compare them to those of other existing immersive digital environments. We review the state-of-the-art of virtual reality technology, and then survey core areas of psychology relevant to experiences in the fulldome, including visual perception, attention, memory, social factors and individual differences. Building on the existing research within these domains, we propose potential directions for empirical investigation that highlight the great potential of the fulldome in teaching, learning and research.
Keywords: Digital fulldome; Immersive Virtual Environment; Virtual reality; Presence; Immersion; Psychology; Learning

IJHCS 2012-09 Volume 70 Issue 9

Using auditory event-related EEG potentials to assess presence in virtual reality BIBAKFull-Text 577-587
  Silvia Erika Kober; Christa Neuper
The feeling of presence in a virtual reality (VR) is a concept without a standardized objective measurement. In the present study, we used event-related brain potentials (ERP) of the electroencephalogram (EEG) elicited by tones, which are not related to VR, as an objective indicator for the presence experience within a virtual environment. Forty participants navigated through a virtual city and rated their sensation of being in the VR (experience of presence), while hearing frequent standard tones and infrequent deviant tones, which were irrelevant for the VR task. Different ERP components elicited by the tones were compared between participants experiencing a high level of presence and participants with a low feeling of presence in the virtual city. Early ERP components, which are more linked to automatic stimulus processing, showed no correlation with presence experience. In contrast, an increased presence experience was associated with decreased late negative slow wave amplitudes, which are associated with central stimulus processing and allocation of attentional resources. This result supports the assumption that increased presence is associated with a strong allocation of attentional resources to the VR, which leads to a decrease of attentional resources available for processing VR-irrelevant stimuli. Hence, ERP components elicited by the tones are reduced. Particularly, frontal negative slow waves turned out to be accurate predictors for presence experience. Summarizing, late ERPs elicited by VR-irrelevant tones differ as a function of presence experience in VR and provide a valuable method for measuring presence in VR.
Keywords: Event-related potentials; Spatial presence; Measuring presence; Virtual reality; Attention allocation; VR-irrelevant stimuli
Realistic electronic books BIBAKFull-Text 588-610
  Veronica Liesaputra; Ian H. Witten
We describe a software book model that emulates a range of properties associated with physical books -- analog page turning, visual location cues, bookmarks and annotations -- and, furthermore, incorporates many advantages of digital environments -- hyperlinks, multimedia, full-text search, automatic identification of synonyms, cross-referencing of key terms with an online encyclopedia, and an automatically generated back-of-the-book index. Usability studies were conducted to compare performance using these books for various reading tasks with HTML, PDF and physical books. Participants completed the tasks more efficiently with the new interface without any loss in accuracy; they also preferred it.
Keywords: Within-document navigation; Within-document search; Usability studies; Wikipedia; Electronic book
Cross-cultural assessment of automatically generated multimodal referring expressions in a virtual world BIBAKFull-Text 611-629
  Ielka van der Sluis; Saturnino Luz; Werner Breitfuß; Mitsuru Ishizuka; Helmut Prendinger
This paper presents an assessment of automatically generated multimodal referring expressions as produced by embodied conversational agents in a virtual world. The algorithm used for this purpose employs general principles of human motor control and cooperativity in dialogues that can be parameterised so as to vary the precision of the pointing gestures and the amount of linguistic information included in the referring expressions. The study assessed how native speakers of English and Japanese perceived three different algorithmic outputs for multimodal referring behaviour in terms of understandability, human-likeness and a social practice (selling). Results show that users generally prefer mobile agents that are economical in their linguistic descriptions to stationary verbose agents. They also show the need for further calibration of the algorithm to accommodate the differences between the two groups. In addition to the detailed description of the set up and results of the study, the paper discusses implications for the design and use of agents, methodological issues that arose while conducting the cross-cultural study and directions for future work.
Keywords: Perception of multimodal referring expressions; Virtual worlds; Dialogue; Translation; Cross-cultural differences
A cognitive-experiential approach to modelling web navigation BIBAKFull-Text 630-651
  Paul van Schaik; Jonathan Ling
Flow experience, the degree to which a person feels involved in a particular activity, is an important influence on human -- computer interaction. Building on Guo and Poole's (2009) model of flow experience in Web navigation, and van Schaik and Ling's (in press) cognitive-experiential approach to modelling interaction experience, this research demonstrates the crucial role of the preconditions of flow experience in human -- computer interaction. In an experiment, the preconditions of flow experience -- but not flow experience proper -- mediated the effects of artefact complexity, task complexity and intrinsic motivation (as a situation-specific trait) on both flow and task outcome. However, preconditions did not predict overall artefact evaluation. Within a staged model of flow experience, the broader implications of this work for human -- computer interaction are explored.
Keywords: User-experience; Model; Flow experience; Cognition; Partial least squares

IJHCS 2012-10 Volume 70 Issue 10

Developing, evaluating and deploying multi-touch systems BIBFull-Text 653-656
  Shamus P. Smith; Elizabeth Burd; Jochen Rick
Establishing a baseline for text entry for a multi-touch virtual keyboard BIBAKFull-Text 657-672
  Paul D. Varcholik; Joseph J., Jr. LaViola; Charles E. Hughes
Multi-touch, which has been heralded as a revolution in human -- computer interaction, provides features such as gestural interaction, tangible interfaces, pen-based computing, and interface customization -- features embraced by an increasingly tech-savvy public. However, multi-touch platforms have not been adopted as "everyday' computer interaction devices that support important text entry intensive applications such as word processing and spreadsheets. In this paper, we present two studies that begin to explore user performance and experience with entering text using a multi-touch input. The first study establishes a benchmark for text entry performance on a multi-touch platform across input modes that compare uppercase-only to mixed-case, single-touch to multi-touch and copy to memorization tasks. The second study includes mouse style interaction for formatting rich text to simulate a word processing task using multi-touch input. As expected, our results show that users do not perform as well in terms of text entry efficiency and speed using a multi-touch interface as with a traditional keyboard. Not as expected was the result that degradation in performance was significantly less for memorization versus copy tasks, and consequently willingness to use multi-touch was substantially higher (50% versus 26%) in the former case. Our results, which include preferred input styles of participants, also provide a baseline for further research to explore techniques for improving text entry performance on multi-touch systems.
Keywords: Multi-touch; Text entry; Speed; Accuracy; Text intensive applications
Design and evaluation of finger-count interaction: Combining multitouch gestures and menus BIBAKFull-Text 673-689
  Gilles Bailly; Jörg Müller; Eric Lecolinet
Selecting commands on multi-touch displays is still a challenging problem. While a number of gestural vocabularies have been proposed, these are generally restricted to one or two fingers or can be difficult to learn. We introduce Finger-Count gestures, a coherent set of multi-finger and two-handed gestures. Finger-Count gestures are simple, robust, expressive and fast to perform. In order to make these gestures self-revealing and easy to learn, we propose the Finger-Count menu, a menu technique and teaching method for implicitly learning Finger-Count gestures. We discuss the properties, advantages and limitations of Finger-Count interaction from the gesture and menu technique perspectives as well as its integration into three applications. We present alternative designs to increase the number of commands and to enable multi-user scenarios. Following a study which shows that Finger-Count is as easy to learn as radial menus, we report the results of an evaluation investigating which gestures are easier to learn and which finger chords people prefer. Finally, we present Finger-Count for in-the-air gestures. Thereby, the same gesture set can be used from a distance as well as when touching the surface.
Keywords: Menu techniques; Multi-touch; Multi-finger interaction; Two-handed interaction
MultiPoint: Comparing laser and manual pointing as remote input in large display interactions BIBAKFull-Text 690-702
  Amartya Banerjee; Jesse Burstyn; Audrey Girouard; Roel Vertegaal
We present MultiPoint, a set of perspective-based remote pointing techniques that allows users to perform bimanual and multi-finger remote manipulation of graphical objects on large displays. We conducted two empirical studies that compared remote pointing techniques performed using fingers and laser pointers, in single and multi-finger pointing interactions. We explored three types of manual selection gestures: squeeze, breach and trigger. The fastest and most preferred technique was the trigger gesture in the single point experiment and the unimanual breach gesture in the multi-finger pointing study. The laser pointer obtained mixed results: it is fast, but inaccurate in single point, and it obtained the lowest ranking and performance in the multipoint experiment. Our results suggest MultiPoint interaction techniques are superior in performance and accuracy to traditional laser pointers for interacting with graphical objects on a large display from a distance.
Keywords: Multi-touch; Remote interaction; Large display; Input device; Interaction technique
Scaling up multi-touch selection and querying: Interfaces and applications for combining mobile multi-touch input with large-scale visualization displays BIBAKFull-Text 703-713
  Daniel F. Keefe; Ankit Gupta; Daniel Feldman; John V. Carlis; Susi Krehbiel Keefe; Timothy J. Griffin
We present a mobile multi-touch interface for selecting, querying, and visually exploring data visualized on large, high-resolution displays. Although emerging large (e.g., 10 m wide), high-resolution displays provide great potential for visualizing dense, complex datasets, their utility is often limited by a fundamental interaction problem -- the need to interact with data from multiple positions around a large room. Our solution is a selection and querying interface that combines a hand-held multi-touch device with 6 degree-of-freedom tracking in the physical space that surrounds the large display. The interface leverages context from both the user's physical position in the room and the current data being visualized in order to interpret multi-touch gestures. It also utilizes progressive refinement, favoring several quick approximate gestures as opposed to a single complex input in order to most effectively map the small mobile multi-touch input space to the large display wall. The approach is evaluated through two interdisciplinary visualization applications: a multi-variate data visualization for social scientists, and a visual database querying tool for biochemistry. The interface was effective in both scenarios, leading to new domain-specific insights and suggesting valuable guidance for future developers.
Keywords: Multi-touch; Progressive refinement; 3D user interface; Mobile device; 3D tracking; Ray casting; Selection
Semiotic analysis of multi-touch interface design: The MuTable case study BIBAKFull-Text 714-728
  Jan Derboven; Dries De Roeck; Mathijs Verstraete
Although multi-touch applications and user interfaces have become increasingly common in the last few years, there is no agreed-upon multi-touch user interface language yet. In order to gain a deeper understanding of the design of multi-touch user interfaces, this paper presents semiotic analysis of multi-touch applications as an interesting approach to gain deeper understanding of the way users use and understand multi-touch interfaces. In a case study example, user tests of a multi-touch tabletop application platform called MuTable are analysed with the Communicability Evaluation Method to evaluate to what extent users understand the intended messages (e.g., cues about interaction and functionality) the MuTable platform communicates. The semiotic analysis of this case study shows that although multi-touch interfaces can facilitate user exploration, the lack of well-known standards in multi-touch interface design and in the use of gestures makes the user interface difficult to use and interpret. This conclusion points to the importance of the elusive balance between letting users explore multi-touch systems on their own on one hand, and guiding users, explaining how to use and interpret the user interface, on the other.
Keywords: Multi-touch; Tabletops; User studies; Semiotics; Evaluation
Assessing the effectiveness of direct gesture interaction for a safety critical maritime application BIBAKFull-Text 729-745
  Frøy Birte Bjørneseth; Mark D. Dunlop; Eva Hornecker
Multi-touch interaction, in particular multi-touch gesture interaction, is widely believed to give a more natural interaction style. We investigated the utility of multi-touch interaction in the safety critical domain of maritime dynamic positioning (DP) vessels. We conducted initial paper prototyping with domain experts to gain an insight into natural gestures; we then conducted observational studies aboard a DP vessel during operational duties and two rounds of formal evaluation of prototypes -- the second on a motion platform ship simulator. Despite following a careful user-centred design process, the final results show that traditional touch-screen button and menu interaction was quicker and less erroneous than gestures. Furthermore, the moving environment accentuated this difference and we observed initial use problems and handedness asymmetries on some multi-touch gestures. On the positive side, our results showed that users were able to suspend gestural interaction more naturally, thus improving situational awareness.
Keywords: Gestural interaction; Multi-touch interaction; User studies; Prototypes; Safety-critical situations
The design, development, and deployment of a tabletop interface for collaborative exploration of genomic data BIBAKFull-Text 746-764
  O. Shaer; M. Strait; C. Valdes; H. Wang; T. Feng; M. Lintz; M. Ferreirae; C. Grote; K. Tempel; S. Liu
In this paper, we reflect on the design, development, and deployment of G-nome Surfer; a multi-touch tabletop user interface for collaborative exploration of genomic data. G-nome Surfer lowers the threshold for using advanced bioinformatics tools, reduces the mental workload associated with manipulating genomic information, and fosters effective collaboration. We describe our two-year-long effort from design strategy to iterations of design, development, and evaluation. This paper presents four main contributions: (1) a set of design requirements for supporting collaborative exploration in data-intensive domains, (2) the design, implementation, and validation of a multi-touch tabletop interface for collaborative exploration, (3) a methodology for evaluating the strengths and limitations of tabletop interaction for collaborative exploration, and (4) empirical evidence for the feasibility and value of integrating tabletop interaction in college-level education.
Keywords: Tabletop interaction; Multi-touch interaction; Bioinformatics; Reality-based interaction; Genome browser; Collaborative learning
The conceptual framing, design and evaluation of device ecologies for collaborative activities BIBAKFull-Text 765-779
  Tim Coughlan; Trevor D. Collins; Anne Adams; Yvonne Rogers; Pablo A. Haya; Estefanía Martín
A variety of computing technologies, in addition to the personal computer, are now commonly used in many settings. As networking infrastructures mature, it is increasingly feasible and affordable to consider closer integration and use of these heterogeneous devices in tandem. However, little is known about how best to design or evaluate such 'device ecologies'; in particular, how best to combine devices to achieve a desired type of collaborative user experience. A central concern is how users switch their attention between devices, to utilize the various elements to best effect. We describe here the development of an ecology of devices for groups of students to use when engaged in collaborative inquiry-learning activities. This included a multi-touch tabletop, laptops, projections, video streams and telephone. In situ studies of students and tutors using it in three different settings showed how individuals and groups switched their foci between the multiple devices. We present our findings, using a novel method for analysing users' transitions between foci, identifying patterns and emergent characteristics. We then discuss the importance of designing for transitions that enable groups to appropriately utilise an ecology of devices, using the concepts of seams, bridges, niches and focal character.
Keywords: Collaboration; Device ecology; Foci of attention; Collaborative learning; Multi-touch; Tabletop; Seams

IJHCS 2012-11 Volume 70 Issue 11

Towards perceptual fidelity: Slant perception in real and interactive virtual environments BIBAKFull-Text 781-793
  Nicholaos Mourkoussis; Fiona Rivera; Tom Troscianko; Rycharde Hawkes; Phil L. Watten; Katerina Mania
An innovative motoric measure of slant based on gait is proposed as the angle between the foot and the walking surface during walking. This work investigates whether the proposed action-based measure is affected by factors such as material and inclination of the walking surface. Experimental studies were conducted in a real environment set-up and in its virtual simulation counterpart evaluating behavioural fidelity and user performance in ecologically-valid simulations. In the real environment, the measure slightly overestimated the inclined path whereas in the virtual environment it slightly underestimated the inclined path. The results imply that the proposed slant measure is modulated by motoric caution. Since the "reality' of the synthetic environment was relatively high, performance results should have revealed the same degree of caution as in the real world, however, that was not the case. People become more cautious when the ground plane was steep, slippery, or virtual.
Keywords: Simulation engineering; Human factors; Perceptual computer graphics
The role of visual complexity and prototypicality regarding first impression of websites: Working towards understanding aesthetic judgments BIBAKFull-Text 794-811
  Alexandre N. Tuch; Eva E. Presslaber; Markus Stöcklin; Klaus Opwis; Javier A. Bargas-Avila
This paper experimentally investigates the role of visual complexity (VC) and prototypicality (PT) as design factors of websites, shaping users' first impressions by means of two studies. In the first study, 119 screenshots of real websites varying in VC (low vs. medium vs. high) and PT (low vs. high) were rated on perceived aesthetics. Screenshot presentation time was varied as a between-subject factor (50 ms vs. 500 ms vs. 1000 ms). Results reveal that VC and PT affect participants' aesthetics ratings within the first 50 ms of exposure. In the second study presentation times were shortened to 17, 33 and 50 ms. Results suggest that VC and PT affect aesthetic perception even within 17 ms, though the effect of PT is less pronounced than the one of VC. With increasing presentation time the effect of PT becomes as influential as the VC effect. This supports the reasoning of the information-processing stage model of aesthetic processing (Leder et al., 2004), where VC is processed at an earlier stage than PT. Overall, websites with low VC and high PT were perceived as highly appealing.
Keywords: Web design; First impression; Visual complexity; Prototypicality; User experience; Website aesthetics
Unpacking the temporal advantage of distributing complex visual displays BIBAKFull-Text 812-827
  Jooyoung Jang; Susan Bell Trickett; Christian D. Schunn; J. Gregory Trafton
Spatial arrangement of information can have large effects on problem solving. Although such effects have been observed in various domains (e.g., instruction and interface designs), little is known about the cognitive processing mechanisms underlying these effects, nor its applicability to complex visual problem solving. In three experiments, we showed that the impact of spatial arrangement of information on problem solving time can be surprisingly large for complex real world tasks. It was also found that the effect can be caused by large increases in slow, external information searches (Experiment 1), that the spatial arrangement itself is the critical factor and the effect is domain-general (Experiment 2a), and that the underlying mechanism can involve micro-strategy selection for information encoding in a response to differing information access cost (Experiment 2b). Overall, these studies show a large slowdown effect (i.e., approximately 30%) that stacking information produces over spatially distributed information, and multiple paths by which this effect can be produced.
Keywords: Information display; Information access cost; Cognitive load theory; Proximity compatibility theory
Virtual grasp release method and evaluation BIBAKFull-Text 828-848
  Mores Prachyabrued; Christoph W. Borst
We address a "sticking object' problem for the release of whole-hand virtual grasps. The problem occurs when grasping techniques require fingers to be moved outside an object's boundaries after a user's (real) fingers interpenetrate virtual objects due to a lack of physical motion constraints. This may be especially distracting for grasp techniques that introduce mismatches between tracked and visual hand configurations to visually prevent interpenetration. Our method includes heuristic analysis of finger motion and a transient incremental motion metaphor to manage a virtual hand during grasp release. We integrate the method into a spring model for whole-hand virtual grasping to maintain the physically-based pickup and manipulation behavior of such models. We show that the new spring model improves release speed and accuracy based on pick-and-drop, targeted ball-drop, and cube-alignment experiments. In contrast to a standard spring-based grasping method, measured release quality does not depend notably on object size. Users subjectively prefer the new approach and it can be tuned to avoid potential side effects such as increased drops or visual distractions. We further investigated a convergence speed parameter to find the subjectively good range and to better understand tradeoffs in subjective artifacts on the continuum between pure incremental motion and rubber-band-like convergence behavior.
Keywords: Interaction techniques; Virtual reality; Virtual grasping; Grasp release
Reconstructing experiences with iScale BIBAKFull-Text 849-865
  Evangelos Karapanos; Jean-Bernard Martens; Marc Hassenzahl
We present iScale, a survey tool for the retrospective elicitation of longitudinal user experience data. iScale aims to minimize retrospection bias and employs graphing to impose a process during the reconstruction of one's experiences. Two versions, the constructive and the value-account iScale, were motivated by two distinct theories on how people reconstruct emotional experiences from memory. These two versions were tested in two separate studies. Study 1 aimed at providing qualitative insight into the use of iScale and compared its performance to that of free-hand graphing. Study 2 compared the two versions of iScale to free recall, a control condition that does not impose structure on the reconstruction process. Overall, iScale resulted in an increase in the amount, the richness, and the test -- retest consistency of recalled information as compared to free recall. These results provide support for the viability of retrospective techniques as a cost-effective alternative to longitudinal studies.
Keywords: User experience evaluation; Retrospective elicitation; Longitudinal methods
A paradigm for handwriting-based intelligent tutors BIBAKFull-Text 866-887
  Lisa Anthony; Jie Yang; Kenneth R. Koedinger
This paper presents the interaction design of, and demonstration of technical feasibility for, intelligent tutoring systems that can accept handwriting input from students. Handwriting and pen input offer several affordances for students that traditional typing-based interactions do not. To illustrate these affordances, we present evidence, from tutoring mathematics, that the ability to enter problem solutions via pen input enables students to record algebraic equations more quickly, more smoothly (fewer errors), and with increased transfer to non-computer-based tasks. Furthermore our evidence shows that students tend to like pen input for these types of problems more than typing. However, a clear downside to introducing handwriting input into intelligent tutors is that the recognition of such input is not reliable. In our work, we have found that handwriting input is more likely to be useful and reliable when context is considered, for example, the context of the problem being solved. We present an intelligent tutoring system for algebra equation solving via pen-based input that is able to use context to decrease recognition errors by 18% and to reduce recognition error recovery interactions to occur on one out of every four problems. We applied user-centered design principles to reduce the negative impact of recognition errors in the following ways: (1) though students handwrite their problem-solving process, they type their final answer to reduce ambiguity for tutoring purposes, and (2) in the small number of cases in which the system must involve the student in recognition error recovery, the interaction focuses on identifying the student's problem-solving error to keep the emphasis on tutoring. Many potential recognition errors can thus be ignored and distracting interactions are avoided. This work can inform the design of future systems for students using pen and sketch input for math or other topics by motivating the use of context and pragmatics to decrease the impact of recognition errors and put user focus on the task at hand.
Keywords: Intelligent tutoring systems; Pen input; Handwriting recognition; Mathematics; Cognitive tutors; Interaction design; Human-computer interaction; Educational technology
Generating phenotypical erroneous human behavior to evaluate human -- automation interaction using model checking BIBAKFull-Text 888-906
  Matthew L. Bolton; Ellen J. Bass; Radu I. Siminiceanu
Breakdowns in complex systems often occur as a result of system elements interacting in unanticipated ways. In systems with human operators, human -- automation interaction associated with both normative and erroneous human behavior can contribute to such failures. Model-driven design and analysis techniques provide engineers with formal methods tools and techniques capable of evaluating how human behavior can contribute to system failures. This paper presents a novel method for automatically generating task analytic models encompassing both normative and erroneous human behavior from normative task models. The generated erroneous behavior is capable of replicating Hollnagel's zero-order phenotypes of erroneous action for omissions, jumps, repetitions, and intrusions. Multiple phenotypical acts can occur in sequence, thus allowing for the generation of higher order phenotypes. The task behavior model pattern capable of generating erroneous behavior can be integrated into a formal system model so that system safety properties can be formally verified with a model checker. This allows analysts to prove that a human -- automation interactive system (as represented by the model) will or will not satisfy safety properties with both normative and generated erroneous human behavior. We present benchmarks related to the size of the statespace and verification time of models to show how the erroneous human behavior generation process scales. We demonstrate the method with a case study: the operation of a radiation therapy machine. A potential problem resulting from a generated erroneous human action is discovered. A design intervention is presented which prevents this problem from occurring. We discuss how our method could be used to evaluate larger applications and recommend future paths of development.
Keywords: Human -- automation interaction; Model checking; Task analysis; Human error; Formal methods

IJHCS 2012-12 Volume 70 Issue 12

Perceptions of web knowledge and usability: When sex and experience matter BIBAKFull-Text 907-919
  Kelly L. Page; Matthew J. Robson; Mark D. Uncles
Web users are now a mixture of consumer and web designer. As such, the context within which we are socialized about the web -- as both male and female users -- moderates the relationship between what we think we know about it and its usability to complete tasks. With online survey data from 2077 web users, we empirically examine the relationship between user perceptions of web knowledge (our confidence in what we think we know) and user beliefs about usability of the web (how easy and useful we believe it to be). We include a user's sex and their website design experience as important moderators on this relationship. Results show a positive relationship between perceived web knowledge and web usability, and under the context of website design experience, more value is placed on the utility of the web, rather than on its ease of use. This moderation effect is stronger for female than it is for male web users. In summary, users with more confidence in their knowledge are more oriented towards the utility of the web than how easy it is to harvest that utility. Our work contributes to an understanding of the influence of the usage context within which the knowledge and beliefs of male and female users are socialized about web technology.
Keywords: Perceived web knowledge; Perceived web usability; Usage context; Website design experience; Gender; Sex
Improving the controllability of tilt interaction for mobile map-based applications BIBAKFull-Text 920-935
  Bradley Paul van Tonder; Janet Louise Wesson
This article proposes enhanced techniques for improving the controllability of tilt interaction. Tilt interaction offers an intuitive, one-handed form of interaction for mobile applications. Tilt interaction is particularly well-suited to mobile map-based applications, where traditional mobile interaction techniques suffer from several shortcomings. Current implementations of tilt interaction, however, suffer from several shortcomings. Existing zooming techniques used in conjunction with tilt interaction are often difficult to control. Tilt-controlled panning can also be difficult to control in a mobile context of use, where the user's walking motion affects the accuracy of tilt interaction. The use of rate-controlled tilt interaction to perform zooming is proposed. Two different approaches to sensitivity adaptation are investigated, where the sensitivity of tilt-controlled panning is automatically adjusted to compensate for the user's current context of use. A usability study was conducted with thirty participants to evaluate the proposed techniques. The results of the usability study showed that tilt zooming offered better efficiency, user satisfaction and perceived workload than gesture zooming. The use of a static dampening factor to compensate for walking motion was found to provide actual and perceived controllability improvements.
Keywords: Tilt interaction; Maps; Controllability; Adaptation
Audemes at work: Investigating features of non-speech sounds to maximize content recognition BIBAKFull-Text 936-966
  Mexhid Ferati; Mark S. Pfaff; Steve Mannheimer; Davide Bolchini
To access interactive systems, blind users can leverage their auditory senses by using non-speech sounds. The structure of existing non-speech sounds, however, is geared toward conveying atomic operations at the user interface (e.g., opening a file) rather than evoking broader, theme-based content typical of educational material (e.g., an historical event). To address this problem, we investigate audemes, a new category of non-speech sounds whose semiotic structure and flexibility open new horizons for the aural interaction with content-rich applications. Three experiments with blind participants examined the attributes of an audeme that most facilitate the accurate recognition of their meaning. A sequential concatenation of different sound types (music, sound effect) yielded the highest meaning recognition, whereas an overlapping arrangement of sounds of the same type (music, music) yielded the lowest meaning recognition. We discuss seven guidelines to design well-formed audemes.
Keywords: Audeme; Acoustic; Blind; Visually impaired; Non-speech sound; Recognition
Warn me now or inform me later: Drivers' acceptance of real-time and post-drive distraction mitigation systems BIBAKFull-Text 967-979
  Shannon C. Roberts; Mahtab Ghazizadeh; John D. Lee
Vehicle crashes caused by driver distraction are of increasing concern. One approach to reduce the number of these crashes mitigates distraction by giving drivers feedback regarding their performance. For these mitigation systems to be effective, drivers must trust and accept them. The objective of this study was to evaluate real-time and post-drive mitigation systems designed to reduce driver distraction. The real-time mitigation system used visual and auditory warnings to alert the driver to distracting behavior. The post-drive mitigation system coached drivers on their performance and encouraged social conformism by comparing their performance to peers. A driving study with 36 participants between the ages of 25 and 50 years old (M=34) was conducted using a high-fidelity driving simulator. An extended Technology Acceptance Model captured drivers' acceptance of mitigation systems using four constructs: perceived ease of use, perceived usefulness, unobtrusiveness, and behavioral intention to use. Perceived ease of use was found to be the primary determinant and perceived usefulness the secondary determinant of behavioral intention to use, while the effect of unobtrusiveness on intention to use was fully mediated by perceived ease of use and perceived usefulness. The real-time system was more obtrusive and less easy to use than the post-drive system. Although this study included a relatively narrow age range (25 to 50 years old), older drivers found both systems more useful. These results suggest that informing drivers with detailed information of their driving performance after driving is more acceptable than warning drivers with auditory and visual alerts while driving.
Keywords: Driver distraction; Distraction mitigation; Feedback; Technology Acceptance Model