HCI Bibliography Home | HCI Journals | About IWC | Journal Info | IWC Journal Volumes | Detailed Records | RefWorks | EndNote | Hide Abstracts
IWC Tables of Contents: 14151617181920212223242526

Interacting with Computers 24

Editors:Dianne Murray
Publisher:Elsevier Science
Standard No:ISSN 0953-5438
Links:Table of Contents
  1. IWC 2012-01 Volume 24 Issue 1
  2. IWC 2012-03 Volume 24 Issue 2
  3. IWC 2012-05 Volume 24 Issue 3
  4. IWC 2012-07 Volume 24 Issue 4
  5. IWC 2012-09 Volume 24 Issue 5
  6. IWC 2012-11 Volume 24 Issue 6

IWC 2012-01 Volume 24 Issue 1

Wireless Face Interface: Using voluntary gaze direction and facial muscle activations for human-computer interaction BIBAKFull-Text 1-9
  Outi Tuisku; Veikko Surakka; Toni Vanhala; Ville Rantanen; Jukka Lekkala
The present aim was to investigate the functionality of a new wireless prototype called Face Interface. The prototype combines the use of voluntary gaze direction and facial muscle activations, for pointing and selecting objects on a computer screen, respectively. The subjective and objective functionality of the prototype was evaluated with a series of pointing tasks using either frowning (i.e., frowning technique) or raising the eyebrows (i.e., raising technique) as the selection technique. Pointing task times and accuracies were measured using three target diameters (i.e., 25, 30, 40 mm), seven pointing distances (i.e., 60, 120, 180, 240, 260, 450, and 520 mm), and eight pointing angles (0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315°). The results showed that the raising technique was faster selection technique than the frowning technique for the objects that were presented in the pointing distances from 60 mm to 260 mm. For those pointing distances the overall pointing task times were 2.4 s for the frowning technique, and 1.6 s for the raising technique. Fitts' law computations showed that the correlations for the Fitts' law model were r = 0.77 for the frowning technique and r = 0.51 for the raising technique. Further, the index of performance (IP) value was 1.9 bits/s for the frowning technique and 5.4 bits/s for raising the eyebrows technique. Based on the results, the prototype functioned well and was adjustable so that two different facial activations can be used in combination with gaze direction for pointing and selecting objects on a computer screen.
Keywords: Eye tracking; Facial muscle activations; Human-computer interaction; Fitts' law
An interactive 3D movement path manipulation method in an augmented reality environment BIBAKFull-Text 10-24
  Taejin Ha; Mark Billinghurst; Woontack Woo
In this paper, we evaluate a path editing method using a tangible user interface to generate and manipulate the movement path of a 3D object in an Augmented Reality (AR) scene. To generate the movement path, each translation point of a real 3D manipulation prop is examined to determine which point should be used as a control point for the path. Interpolation using splines is then used to reconstruct the path with a smooth line. A dynamic score-based selection method is also used to effectively select small and dense control points of the path. In an experimental evaluation, our method took the same time and generated a similar amount of errors as a more traditional approach, however the number of control points needed was significantly reduced. For control manipulation, the task completion time was quicker and there was less hand movement needed. Our method can be applied to drawing or curve editing methods in AR educational, gaming, and simulation applications.
Keywords: Immersive augmented reality; Augmented reality authoring; Movement path editing; Tangible user interface; 3D object selection and manipulation
Understanding the most satisfying and unsatisfying user experiences: Emotions, psychological needs, and context BIBAKFull-Text 25-34
  Timo Partala; Aleksi Kallinen
The aim of this research was to study the structure of the most satisfying and unsatisfying user experiences in terms of experienced emotions, psychological needs, and contextual factors. 45 university students wrote descriptions of their most satisfying and unsatisfying recent user experiences and analyzed those experiences using the Positive and Negative Affect Schedule (PANAS) method for experienced emotions, a questionnaire probing the salience of 10 psychological needs, and a self-made set of rating scales for analyzing context. The results suggested that it was possible to capture variations in user experiences in terms of experienced emotions, fulfillment of psychological needs, and context effectively by using psychometric rating scales. The results for emotional experiences showed significant differences in 16 out of 20 PANAS emotions between the most satisfying and unsatisfying experiences. The results for psychological needs indicated that feelings of autonomy and competence emerged as highly salient in the most satisfying experiences and missing in the unsatisfying experiences. High self-esteem was also notably salient in the most satisfying experiences. The qualitative results indicated that most of the participants' free-form qualitative descriptions, especially for the most unsatisfying user experiences, gave important information about the pragmatic aspects of the interaction, but often omitted information about hedonic and social aspects of user experience.
Keywords: User experience; Emotion; Psychological need; Context
An experimental study of learner perceptions of the interactivity of web-based instruction BIBAKFull-Text 35-48
  Jui-ni Sun; Yu-chen Hsu
An effectively designed interaction mechanism creates a shortcut for human-computer interaction. Most studies in this area have concluded that the higher the level of interactivity, the better, especially regarding interactive websites applied in the fields of business and education. Previous studies have also suggested that designs with a higher level of interactivity result in higher learner evaluations of websites. However, little research has examined learner perceptions as they interact with web-based instruction (WBI) systems in a situation with limited time. To assist learners in acquiring knowledge quickly, the interactivity design must make the web learning environment easier to use by reducing the complexity of the interface. The aim of the present study is to explore learner perceptions of three WBI systems with different interaction levels under time limitations. This study was therefore designed to provide a new framework to design systems with different degrees of interactivity, and to examine learners' perceptions of these interaction elements. Three WBI systems were developed with different degrees of interactivity from high to low, and a between-subject experiment was conducted with 45 subjects. The results of the experiment indicate that a higher level of interactivity does not necessarily guarantee a higher perception of interactivity in a short-term learning situation. Therefore, the instructors must pay attention to modifying or selecting appropriate interactive elements that are more suitable for various learning stages. The findings provide insights for designers to adopt different degrees of interactivity in their designs that will best fulfill various learners' needs.
Keywords: Interactivity levels; Web-based instruction; Interaction design; Learner perception

IWC 2012-03 Volume 24 Issue 2

Querying event sequences by exact match or similarity search: Design and empirical evaluation BIBAKFull-Text 55-68
  Krist Wongsuphasawat; Catherine Plaisant; Meirav Taieb-Maimon; Ben Shneiderman
Specifying event sequence queries is challenging even for skilled computer professionals familiar with SQL. Most graphical user interfaces for database search use an exact match approach, which is often effective, but near misses may also be of interest. We describe a new similarity search interface, in which users specify a query by simply placing events on a blank timeline and retrieve a similarity-ranked list of results. Behind this user interface is a new similarity measure for event sequences which the users can customize by four decision criteria, enabling them to adjust the impact of missing, extra, or swapped events or the impact of time shifts. We describe a use case with Electronic Health Records based on our ongoing collaboration with hospital physicians. A controlled experiment with 18 participants compared exact match and similarity search interfaces. We report on the advantages and disadvantages of each interface and suggest a hybrid interface combining the best of both.
Keywords: Temporal categorical data; Event sequence; Temporal query interface; Similarity search; Similarity measure; Similan
Using think-aloud and psychometrics to explore users' experience with a news Web site BIBAKFull-Text 69-77
  Gabor Aranyi; Paul van Schaik; Philip Barker
The present study is part of a research programme that aims to develop and test a psychological model of end-users' experience with news sites. An exploratory study of interaction experience with a news Web site was conducted. An online questionnaire was used to collect information on demographics, Internet-use and news-site use behaviour of users of a particular news site, and to recruit participants for a think-aloud study. The protocol analysis of screen-capture and audio recordings of participants, who used a news site while thinking aloud, yielded five categories of experience: impression, content, layout, information architecture and diversion. These categories are regarded as spontaneous, self-reported aspects of users' experience with a news site. A set of interaction-experience questionnaires revealed significant differences between regular users and non-users of a news site. Correlation and regression analyses demonstrated support for Hassenzahl's model of interaction experience. The study presents a first attempt to empirically investigate the aspects of interaction experience in relation to online news sites.
Keywords: Interaction experience; Online news; Think-aloud; Psychometrics
Interpretation and generation incremental management in natural interaction systems BIBAKFull-Text 78-90
  David del Valle-Agudo; Javier Calle-Gómez; Dolores Cuadra-Fernández; Jessica Rivero-Espinosa
Human interaction develops as an exchange of contributions between participants. The construction of a contribution is not an activity unilaterally created by the participant who produces it, but rather it constitutes a combined activity between the producer and the rest of the participants who take part in the interaction, by means of simultaneous feedback. This paper presents an incremental approach (without losing sight of how turns are produced throughout time), in which the interpretation of contributions is done as they take place, and the final generated contributions are the result of constant rectifications, reformulations and cancellations of the initially formulated contributions. The Continuity Manager and the Processes Coordinator components are proposed. The integration of these components in natural interaction systems allow for a joint approach to these problems. Both have been implemented and evaluated in a real framework called LaBDA-Interactor System which has been applied to the "dictation domain'. We found that the degree of naturalness of this turn-taking approach is very close to the human one and it significantly improves the interaction cycle.
Keywords: Human computer interaction; Natural interaction; Presentation manager; Incremental interpretation; Incremental generation; Continuity management
Fast and independent access to map directions for people who are blind BIBAKFull-Text 91-106
  Zheshen Wang; Nan Li; Baoxin Li
This article presents an automatic approach, complete with a prototype system, to supporting fast and independent access to online maps for local navigation by people with visual impairment. With user-inputted start and end addresses from a keyboard, the approach first queries MapQuest (www.mapquest.com) for obtaining the walking directions and the corresponding map image. Then, it automatically converts the obtained information in a form that can be reproduced immediately through a tactile printer, and subsequently generates an SVG (Scalable Vector Graphics) file, which associates textual descriptions of the directions with a recreated tactile map. The tactile hard copy can be placed on a touchpad which is connected to a computer. With the generated SVG file opened in the computer, a user can explore the tactile map by hands, receiving instant audio feedback of the directions by pressing certain regions with special tactile patterns. This approach supports instant queries of walking directions without requiring tedious manual conversion by a sighted professional. The audio-tactile patterns, the adaptive representation scheme and the blind-friendly user interface are specifically designed for the visually-impaired users. Results from experimental evaluation based on a group of users with visual impairment suggest that the proposed approach is effective for providing blind computer users with independent access to geographic directions.
Keywords: Tactile map; Accessibility; Multi-modal system; Visual impairment

IWC 2012-05 Volume 24 Issue 3

User-friendly locations of error messages in web forms: Put them on the right side of the erroneous input field BIBAKFull-Text 107-118
  Mirjam Seckler; Alexandre N. Tuch; Klaus Opwis; Javier A. Bargas-Avila
There are many ways of placing error messages in web forms. A study of web conventions shows that the most common approach is to display error messages embedded in the form at the top of the entire form. Six frequent locations (right, left, above and below the erroneous input field, as well as on the top and at the bottom of the form) were tested in an online study with n = 303 participants. Results of efficiency, effectiveness and satisfaction show that the locations near the erroneous input field lead to a significantly better performance than the error messages on the top and at the bottom of the form; in addition error messages on the right side of the erroneous input field were subjectively evaluated as the most satisfying and intuitive by participants. The results indicate possible improvements for online shops, where error messages are currently mostly placed on the top of the form.
Keywords: Error message location; Online forms; Display errors; Form usability; Form validation; Interaction design
Acting by hand: Informing interaction design for the periphery of people's attention BIBAKFull-Text 119-130
  Saskia Bakker; Elise van den Hoven; Berry Eggen
Interactions in and with the physical world have enabled us to perform everyday activities in the periphery of our attention. Even though digital technologies are becoming increasingly present in the everyday environment, interaction with these technologies usually requires people's focused attention. In the realm of the vision of calm technology, we think that designing interactions with the digital world inspired by our peripheral interaction with the physical world, will enable digital technologies to better blend into our everyday lives. However, for such interaction design to be effective, a detailed understanding of the everyday periphery is required. In this paper, we therefore present a qualitative study on everyday activities that may take place in the periphery of the attention. We provide a broad range of examples of such everyday activities and cluster them to present the conditions under which they may be performed peripherally. Furthermore, we discuss how our findings may be relevant for the design of peripheral interactions with digital technologies, and present two conceptual designs that are based on our findings.
Keywords: Interaction design; Periphery; Attention; User-centered design; Tangible interaction; Embodied interaction
Positive mood induction procedures for virtual environments designed for elderly people BIBAKFull-Text 131-138
  R. M. Baños; E. Etchemendy; D. Castilla; A. García-Palacios; S. Quero; C. Botella
Positive emotions have a significant influence on mental and physical health. Their role in the elderly's wellbeing has been established in numerous studies. It is therefore worthwhile to explore ways in which elderly people can increase the number of positive experiences in their daily lives. This paper describes two Virtual Environments (VEs) that were used as mood induction procedures (MIPs) for this population. In addition, the VEs' efficacy at increasing joy and relaxation in elderly users is analyzed. The VEs contain exercises for generating positive-autobiographic memories, mindfulness and slow breathing rhythms. The total sample comprised 18 participants over 55 years old who used the VEs on two occasions. Twelve of them used the joy environment, while 16 used the relaxation environment. Moods before and after each session were assessed using Visual Analogical Scales. After using both VEs, results indicated significant increases in joy and relaxation and significant decreases in sadness and anxiety. The participants also indicated low levels of difficulty of use and high levels of satisfaction and sense of presence. Hence, the VEs demonstrate their usefulness at promoting positive affects and enhancing the wellbeing of elderly people.
Keywords: Elderly people; Mood induction procedures; Virtual reality; Positive emotions; e-Health; ICTs
Gender affordances of conversational agents BIBAKFull-Text 139-153
  Sheryl Brahnam; Antonella De Angeli
Conversational agents are attributed human-like characteristics; in particular, they are often assumed to have a gender. There is evidence that gender sets up expectations that have an impact on user experiences with agents. The objective of this paper is to explore gender affordances of conversational agents. Our examination takes a holistic approach to the analysis of the application of gender stereotypes to nine chatterbots: six embodied (three male and three female), two disembodied (male and female), and a robot embodiment. Building on social psychology research, we test the persistence of gender stereotypes in the selection of conversation topics and in the elicitation of disinhibition and verbal abuse. Our study is based on quantitative textual analysis of interaction logs. A dictionary of English sexual slang and derogatory terms was developed for this study. Results show that gender stereotypes tend to affect interaction more at the relational (style) level then at the referential (content) level of conversation. People attribute negative stereotypes to female-presenting chatterbots more often than they do to male-presenting chatterbots, and female-presenting chatterbots are more often the objects of implicit and explicit sexual attention and swear words. We conclude by calling for a more informed analysis of user interactions that considers the full range of user interactions.
Keywords: Sexuality and HCI; LIWC; Gender; Agent abuse; Embodied conversational agents; Sex stereotypes
A survey of methods for data fusion and system adaptation using autonomic nervous system responses in physiological computing BIBAKFull-Text 154-172
  Domen Novak; Matjaz Mihelj; Marko Munih
Physiological computing represents a mode of human -- computer interaction where the computer monitors, analyzes and responds to the user's psychophysiological activity in real-time. Within the field, autonomic nervous system responses have been studied extensively since they can be measured quickly and unobtrusively. However, despite a vast body of literature available on the subject, there is still no universally accepted set of rules that would translate physiological data to psychological states. This paper surveys the work performed on data fusion and system adaptation using autonomic nervous system responses in psychophysiology and physiological computing during the last ten years. First, five prerequisites for data fusion are examined: psychological model selection, training set preparation, feature extraction, normalization and dimension reduction. Then, different methods for either classification or estimation of psychological states from the extracted features are presented and compared. Finally, implementations of system adaptation are reviewed: changing the system that the user is interacting with in response to cognitive or affective information inferred from autonomic nervous system responses. The paper is aimed primarily at psychologists and computer scientists who have already recorded autonomic nervous system responses and now need to create algorithms to determine the subject's psychological state.
Keywords: Affective computing; Physiological computing; Psychophysiology; Data fusion; Autonomic nervous system

IWC 2012-07 Volume 24 Issue 4

Reprint of a process model for developing usable cross-cultural websites BIBAKFull-Text 174-187
  Andy Smith; Lynne Dunckley; Tim French; Shailey Minocha; Yu Chang
In this paper we present a process model for developing usable cross-cultural websites. Compatible with ISO 13407, the process model documents an abstraction of the design process focusing on cultural issues in development. It provides a framework in which a variety of user-based and expert-based techniques for analysis and design are placed within the life-cycle of website development. In developing the model, we relate practical approaches to design with theories and models of culture and discuss the relevance of such theories to the practical design process. In particular we focus on four key concerns: how an audit of local website attractors can inform the design process; the concept of a cultural fingerprint to contrast websites with the cultural needs of local users; the problems associated with user evaluation; and cross-cultural team development. We then show their relation to our process model. We conclude by summarising our contribution to date within the field.
Keywords: Cross-cultural usability; Websites; Globalisation; Cultural fingerprint; Attractors; User evaluation
Special issue: Presence and interaction BIBFull-Text 190-192
  John Waterworth; Eva Lindh Waterworth; Fabrizia Mantovani; Giuseppe Riva
Presence and general principles of brain function BIBAKFull-Text 193-202
  Daniel Sjölie
Recent developments in general theories of cognition and brain function make it possible to consider the concept of presence from a new perspective, based in general principles of brain function. The importance of interaction with reality for the development and function of the brain and human cognition is increasingly emphasized. The brain is explained as implementing a generative model of the current environment. Whether this environment is real or virtual does not matter. Mental simulations are created for whatever one interacts with, when possible. This view provides a basis for relating human experiences in virtual environments to several theories that explain cognition and brain function on many levels, from ultimate evolutionary motivations to plausible neural implementations. The purpose of this paper is not to provide yet another definition of presence but to suggest explanations of phenomena commonly related to presence, with a basis in general principles of brain function. Such principles are employed to explain how, and why, interaction with our environment, and internalization of objects and tools therein, play an essential role in human cognition. This provides a rich basis for further analysis of how central aspects of presence, such as breaks in presence or the perceptual illusion of non-mediation, may work on a fundamental level. More general descriptions of such phenomena have advantages such as being easier to relate to new contexts and technologies, and opening up for additional inspiration and confirmation from other disciplines such as cognitive neuroscience. In addition to an account of general principles for brain function and a discussion about the concept of presence in light of these, this paper also relates this discussion to a number of previous accounts of presence, and to practical implications and applications for interaction design.
Keywords: Presence; Brain function; Virtual reality; Cognitive neuroscience
From the body to the tools and back: A general framework for presence in mediated interactions BIBAKFull-Text 203-210
  Giuseppe Riva; Fabrizia Mantovani
Different neuropsychological studies clearly show that the perception of our body and its surrounding space is not a given fact but it is influenced by the outcome of our actions (both direct and mediated by the use of tools). In this view, a possible starting point for a better understanding of Presence in computer-mediated interactions is the study of mediated action and its effects on our spatial experience.
   Following a cognitive perspective, the presented framework describes Presence as an intuitive feeling which is the outcome of an experience-based metacognitive judgment that controls our action. This process monitors pre-reflexively our activity by using an embodied intuitive simulation of the intended action developed through practice (implicit learning).
   When actions are implemented using one or more tools, it is possible to distinguish between two different types of mediated action: first-order (I use the body to control a proximal artifact, e.g. a tennis player striking the ball with the racquet) or second-order (I use the body to control a proximal artifact that controls a different distal one, e.g. a cranemen using a lever to move a mechanical boom to lift materials). These two mediated actions, when produced intuitively, have different effects on our experience of body and space: a successfully learned first-order mediated action produces incorporation -- the proximal tool extends the peripersonal space of the subject -- while a successfully learned second-order mediated action produces also incarnation -- a second peripersonal space centered on the distal tool.
Keywords: Spatial presence; Media presence; Tools; Intuition; Metacognition; Telepresence
Embodiment and telepresence: Toward a comprehensive theoretical framework BIBAKFull-Text 211-218
  Antal Haans; Wijnand A. IJsselsteijn
What explains the experience of "being there' in a simulated or mediated environment? In recent years, research has pointed to various technological and psychological factors deemed important in eliciting this so-called experience of telepresence, including interactivity, sensory-motor integration, media transparency, and distal attribution. However, few theories exist that can combine these findings in a coherent framework. In the present paper, we formulate such a theoretical framework. We will argue that the experience of telepresence is a consequence of the way in which we are embodied, and that it extends naturally from the same ability that allows us to adjust to a slippery surface, or to the weight of a hammer. The importance of embodiment in the understanding of telepresence has been stated before, but these works have not yet fully addressed what it means to be embodied. We argue that "having a human body' means having a specific morphology, a body schema, and a body image. Subsequently we describe how tools and technological artifacts may be incorporated at each of these levels of embodiment, and the implications thereof for the experience of telepresence.
Keywords: Media technology; Presence; Embodiment; Body schema; Body image; Sensory-motor integration
Presence in blended spaces BIBAKFull-Text 219-226
  David Benyon
Mixed reality technologies have been around for over 10 years but it is only with the proliferation of smart phones and tablet (computers) that mixed and augmented reality interaction is reaching the mass market. There are now enough examples of mixed reality interactions that we can begin to abstract principles of design and principles of user experience (UX) for these new spaces of interaction. In this paper I develop the notion of mixed reality as a blended space. Mixed reality is a blend of a physical space and a digital space. The term 'blend' here is borrowed from blending theory which is a theory of cognition that highlights the importance of cross domain mappings and conceptual integration to our thought process that are grounded in physically-based spatial schemas. The concept of a blended space is developed by recognizing that physical space and digital space can both be described in terms of the objects and agents who inhabit the space, the structure of the objects' relationships (the topology of the space) and the changes that take place in the space (the volatility, or dynamics of the space). The blended space will be more effective if the physical and digital spaces have some recognizable and understandable correspondences. The issue of presence in this blended space is then discussed and it is suggested that traditional definitions of presence are inadequate to describe the experiences that blended spaces offer. Presence is considered as interaction between the self and the content of the medium within which the self exists, and place is this medium. Blended spaces mean that people have an extended presence; from their physical location into digital worlds.
Keywords: Presence; User experience; Interaction; Blending theory; Blended spaces
Manipulating subjective realism and its impact on presence: Preliminary results on feasibility and neuroanatomical correlates BIBAKFull-Text 227-236
  Stéphane Bouchard; Stéphanie Dumoulin; Jeanne Talbot; André-Anne Ledoux; Jennifer Phillips; Johana Monthuy-Blanc; Geneviève Labonté-Chartrand; Geneviève Robillard; Matteo Cantamesse; Patrice Renaud
The feeling of presence has been shown to be an important concept in several clinical applications of virtual reality. Among the factors influencing presence, realism factors have been examined extensively from the angle of objective realism. Objective realism has been manipulated by altering numerous technological characteristics such as pictorial quality, texture and shading, or by adding more sensory information (i.e., smell, touch). Much less studied is the subjective (or perceived) realism, the focus of the two pilot studies reported in this article. In Study 1, subjective realism was manipulated in order to assess the impact on the feeling of presence. Method: Presence was measured in 31 adults after two immersions in virtual reality. Participants were immersed in a neutral/irrelevant virtual environment and subsequently subjected to the experimental manipulation. Participants in the experimental condition were falsely led to believe that they were immersed live in real time in a "real' room with a "real' mouse in a cage. In the control condition, participants believed they were immersed in a replica of the nearby room. All participants were actually immersed in the exact same virtual environment. Results: A manipulation check revealed that 80% of the participants believed in the deception. A 2 Times by 2 Conditions repeated measure ANOVA revealed that leading people to believe they were seeing a real environment digitized live in virtual reality increased their feeling of presence compared to the control condition. In Study 2, the same experimental design was used but with simultaneous functional magnetic resonance imaging (fMRI) in order to assess brain areas potentially related to the feeling of presence. fMRI data from five participants were subjected to a within subject fixed effect analysis to verify differences between the experimental immersion (higher presence) and the control immersion (lower presence). Results revealed a statistically significant difference in left and right parahippocampus areas. Conclusion: Results are discussed according to layers of presence and consciousness and the meaning given to experiences occurring in virtual reality. Some suggestions are formulated to target core presence and extended presence.
Keywords: Feeling of presence; Virtual reality; Subjective realism; fMRI; Parahippocampus
Interacting with the Music Paint Machine: Relating the constructs of flow experience and presence BIBAKFull-Text 237-250
  Luc Nijs; Pieter Coussement; Bart Moens; Denis Amelinck; Micheline Lesaffre; Marc Leman
In this paper we report on the results of an experiment on the experience of flow and presence while engaging with an interactive music system, the Music Paint Machine. This music system provides a game-like environment in which a musician can create a digital painting by playing an acoustic musical instrument, by moving the body in different directions, and by selecting colours using a pressure mat. The experiment aimed at getting a better insight into the possible relationship between flow experience and presence. Based on the definition of flow as a combination of the highest level of presence (presence-as-feeling) and a positive emotional state (Riva et al., 2004a), we hypothesized that presence has a predictive value for flow. Sixty-five musicians, both amateur and professional, participated in the experiment. Flow experience was measured with the Flow State Scale (Jackson and Eklund, 2004). Presence was measured with an in-house designed presence questionnaire. Results showed a significantly strong correlation between flow and presence. Moreover, the scores for presence significantly predicted the Flow State Scale, and explained a significant proportion of variance in the Flow State Scale. Furthermore, many significant associations were found between flow and presence variables, among which the most significant were the strong correlation (Spearman's rank) between the naturalness of using the system and the Flow State Scale and between the feeling of non-mediation and the Flow State Scale.
Keywords: Interactive music system; Flow experience; Presence; Embodied music cognition; Embodied interaction
The effects of egocentric and allocentric representations on presence and perceived realism: Tested in stereoscopic 3D games BIBAKFull-Text 251-264
  Sangwon Bae; Haein Lee; Hyejin Park; Hanju Cho; Joonah Park; Jinwoo Kim
Recently, stereoscopic 3D technologies have come to be used widely in various applications including movies and computer games. Stereoscopic 3D is defined as that which provides visual depth and details by exploiting the stereoscopic vision of the eyes caused by binocular disparity. Prior studies proposed important system features of stereoscopic 3D that may increase the user's sense of presence. However, few studies, either theoretical or empirical, have investigated how these perceived system features affect the user's sense of presence. This study aims to construct a theoretical model that explains the perceived effects of stereoscopic 3D features on sense of presence, and to verify the validity of the model in the 3D computer game domain. The study focuses on spatial representation and perceived realism as important mediating factors between the perceived system features and sense of presence. According to the Dual Mode Model (DMM), two types of spatial representation are crucial for perceived realism and presence: egocentric representation and allocentric representation. Egocentric representation implies representing locations with respect to the particular perspective of the perceiver, while allocentric representation locates reference points outside of the perceiver, regardless of his or her position. Research questions in this study are: How strongly do perceived expression and manipulation features of stereoscopic 3D systems influence spatial representation? How does spatial representation influence perceived realism and presence in a stereoscopic 3D environment? In order to answer these research questions an empirical study was conducted in a controlled lab environment. A total number of 257 users participated in the study and collected data was analyzed by using structural equation modeling with SmartPLS2.0. The findings are as follows: First, both the perceived expression and manipulation features of the stereoscopic 3D system influenced spatial representation, but the perceived expression features had stronger effects than the perceived manipulation features. Second, both egocentric and allocentric representation were found to affect presence. In addition, egocentric representation was found to affect sense of presence both directly and indirectly through perceived realism, whereas allocentric representation contributed a sense of presence only indirectly through perceived realism. This paper concludes by discussing the study's limitations and implications.
Keywords: Sense of presence; Perceived realism; Dual mode model; Egocentric representation; Allocentric representation; Perceived manipulation
May I experience more presence in doing the same thing in virtual reality than in reality? An answer from a simulated job interview BIBAKFull-Text 265-272
  D. Villani; C. Repetto; P. Cipresso; G. Riva
Is it possible to experience more presence in doing the same thing in virtual reality than in reality? According to the well known definition of presence as "disappearance of mediation', the answer is no: technology is a barrier, a mediating tool that can only reduce the level of presence experienced in an interaction. However, the increasing diffusion of a technology like augmented reality that adds a technological layer of information to the real world suggests the opposite: the experience of "being there' may be influenced by the ability of "making sense there'.
   To explore this issue we used a sample of 20 university students to evaluate the level of presence experienced in two different settings: an immersive virtual reality job simulation and a real world simulation that was identical to its VR counterpart (same interviewer, same questions) but without technological mediation and without any social and cultural cues in the environment that may give a better meaning to both the task and its social context.
   Self-report data, and in particular the scores in the Spatial Presence and the Ecological Validity ITC-SOPI scales, suggest that experienced presence was higher during the virtual interview than in the real world simulation. This interpretation was confirmed by subjective (higher in VR) but not by objective (Skin Conductance) anxiety scores. These data suggest a vision of presence as a social construction, in which reality is co-constructed in the relationship between actors and their environments through the mediation of physical and cultural artifacts.
Keywords: Presence; Virtual reality; Job interview; Anxiety state
Does locality make a difference? Assessing the effectiveness of location-aware narratives BIBAKFull-Text 273-279
  Evangelos Karapanos; Mary Barreto; Valentina Nisi; Evangelos Niforatos
With the increasing sophistication of mobile computing, a growing interest has been paid to locative media that aim at providing immersive experiences. Location aware narratives are a particular kind of locative media that aim at "telling stories that unfold in real space'. This paper presents a study that aimed at assessing an underlying hypothesis of location-aware narratives: that the coupling between the physical space and the narrative will result in increased levels of immersion in the narrative. Forty-five individuals experienced a location-aware video narrative in three locations: (a) the original location that contains physical cues from the narrative world, (b) a different location that yet portrays a similar atmosphere, and (c) a location that contains neither physical cues nor a similar atmosphere. Significant differences were found in users' experiences with the narrative in terms of immersion in the story and mental imagery, but not with regard to feelings of presence, emotional involvement or the memorability of story elements. We reflect on these findings and the implications for the design of location-aware narratives and highlight questions for further research.
Keywords: Location-aware narratives; Locative media; Narrative transportation; Presence
Age differences in the perception of social presence in the use of 3D virtual world for social interaction BIBAKFull-Text 280-291
  Panote Siriaraya; Chee Siang Ang
3D virtual worlds are becoming increasingly popular as tool for social interaction, with the potential of augmenting the user's perception of physical and social presence. Thus, this technology could be of great benefit to older people, providing home-bound older users with access to social, educational and recreational resources. However, so far there have been few studies looking into how older people engage with virtual worlds, as most research in this area focuses on younger users. In this study, an online experiment was conducted with 30 older and 30 younger users to investigate age differences in the perception of presence in the use of virtual worlds for social interaction. Overall, we found that factors such as navigation and prior experience with text messaging tools played a key role in older people's perception of presence. Both physical and social presence was found to be linked to the quality of social interaction for users of both age groups. In addition, older people displayed proxemic behavior which was more similar to proxemic behavior in the physical world when compared to younger users.
Keywords: Virtual worlds; Presence; Older people; Social interaction; Proxemics
Video-mediated and co-present gameplay: Effects of mutual gaze on game experience, expressiveness and perceived social presence BIBAKFull-Text 292-305
  Suleman Shahid; Emiel Krahmer; Marc Swerts
We study how pairs of children interact socially and express their emotions while playing games in different communicative settings. In particular, we study how such interactions can vary for environments that differ regarding the level of mediation and the associated feelings of social presence. Overall, the study compared three conditions (one face-to-face gameplay condition, and two video-mediated gameplay conditions; one allowing for mutual gaze, the other not) and focused on the social presence and non-verbal behavior of children in three conditions. The results show that the presence of mutual eye-gaze enriches the feelings of social presence, fun and game experience; conversely, the absence of mutual eye-gaze dramatically effects the quality of interaction in the video-mediated environment. The results of this study stress the importance of mutual gaze, and we therefore argue that it should become an integral component of future VMC systems, particularly in those designed for playful settings and children.
Keywords: Video-mediated communication; Mutual gaze; Social presence; Games; Fun; Children
Physiological compliance for social gaming analysis: Cooperative versus competitive play BIBAKFull-Text 306-316
  Guillaume Chanel; J. Matias Kivikangas; Niklas Ravaja
We report the results of an empirical study demonstrating the value of using physiological compliance as a measure of social presence during digital game playing. The physiological activity (facial EMG, electrodermal activity, cardiac activity and respiration) of 21 dyads were acquired synchronously while they were playing a digital game either cooperatively or competitively and either at home or in the laboratory. Physiological compliance was defined as the correlation between the physiological signals of the dyad members. The results of this study confirm that physiological compliance is higher in a conflicting situation than when playing cooperatively. Importantly, the results also demonstrate that physiological compliance is related to self-reported social presence. This suggests that physiological compliance is not limited to negative situations but rather increases due to rich interactions. Only minor differences in physiological compliance were observed between home play and laboratory play, suggesting the ecological validity of laboratory measures. Finally, we propose that compliance measures can be considered as objective indices of social presence in digital gaming.
Keywords: Physiological compliance; Digital games; Social presence; Facial electromyography; Electrodermal activity; Cardiac activity
Subjective and behavioral presence measurement and interactivity in the collaborative augmented reality game TimeWarp BIBAKFull-Text 317-325
  Astrid M. von der Pütten; Jennifer Klatt; Simon Ten Broeke; Roderick McCall; Nicole C. Krämer; Richard Wetzel; Lisa Blum; Leif Oppermann; Johannes Klatt
Presence is usually assessed via a variety of subjective and objective measures. However, constraints often result in subjective measurements using questionnaires as a key method of data collection. In this paper we present a study of 44 participants of a collaborative augmented reality game known as TimeWarp which used both subjective and objective behavioral measures. Behavior as coded from video recordings of one scene of the game and self-reports about feelings of presence were compared. Our findings indicate that pointing behavior and verbal responses to the virtual content are correlated negatively to sense of presence. We further investigated the influence of subjectively perceived interactivity on perceived presence. We found that the interaction possibilities perceived by the participants predicted their experience of social presence with the virtual characters in the game. Furthermore, playing together with another person did not result in decreased social presence of the virtual characters. Implications for presence research are discussed.
Keywords: Presence in games; Behavioral measures; Augmented reality; Collaborative games; Interactivity

IWC 2012-09 Volume 24 Issue 5

The Digital Reading Desk: A lightweight approach to digital note-taking BIBAKFull-Text 327-338
  Jennifer Pearson; George Buchanan; Harold Thimbleby; Matt Jones
Attentive reading is a complex and cognitively demanding task that uses note-taking and annotation to support the reader's interpretation of the document. When reading on paper, extensive use of highlighting and other activities are conducted to support attentive reading, but this rich behaviour is not used with digital documents. Many users therefore print digital documents and then interact with them in physical form.
   This paper presents the "Digital Reading Desk,' an enhanced digital reading environment that provides support for attentive reading, providing a large working space for notes that mimics the use of desk space in a conventional physical environment. The Reading Desk uses a single tool to support both annotation and bookmarking, simplifying both the user's learning of the system and their use of tools. Evaluation of the Reading Desk indicates preference for it, as well as considerable behavioural differences between our approach and traditional digital reading tools.
Keywords: Annotation; Bookmarking; Documents; Notes; Direct manipulation
User interactions with an affective nutritional coach BIBAKFull-Text 339-350
  Christopher Creed; Russell Beale
This paper investigates how users respond to emotional expressions displayed by an embodied agent. In a between-subjects experiment (N = 50) an emotionally expressive agent (simulating the role of a nutritional coach) was perceived as significantly more likeable and caring than an unemotional version. Feedback from participants also revealed detailed insights into their perceptions of the agents and highlighted a strong preference for the emotionally expressive version. Design implications for embodied agents are discussed and future research areas identified.
Keywords: Emotion; Affect; Behaviour change; Engagement; Avatar
The impact of paper prototyping on card sorting: A case study BIBAKFull-Text 351-357
  Karin Slegers; Verónica Donoso
Combining the techniques of paper prototyping and card sorting into a single session has the benefits of helping users to understand a new technology on the one hand, and of gaining insight into the users' mental models of that technology on the other hand. However, acquainting users with a new technology via a paper prototype might affect their mental models, as assessed with the card sorting technique. The aim of this paper was to explore the possibility of combining the two techniques in a single research session. Thirty-seven users participated in a study concerning a payment system based on Near Field Communication (NFC). Eight group sessions were organized, including both a paper prototyping exercise and a card sorting exercise. The order of the exercises was alternated. The findings of this case study seem to suggest that the paper prototyping exercise resulted into deeper insights into the participants' mental models resulting from the card sorting exercise. At the same time, paper prototyping seemed to prevent participants to come up with new names for their card sorting categories.
Keywords: Card sorting; Methodology; Paper prototyping; Near Field Communication; User-centered design; User interfaces
Of organization, device and context: Interruptions from mobile communication in highly specialized care BIBAKFull-Text 358-373
  Jeremiah Scholl; Kristina Groth
This paper presents an ethnographic study of mobile communication at a surgical unit in Sweden involved with highly specialized care for the upper abdomen. The primary focus of the study is interruptions related to usage of mobile communication, with the goal of informing the design of systems that better balance interruptions and availability. The department uses a patchwork of hospital pagers, personal cell phones, and department provided cell phones. Issues related to social factors at the department, technical features of mobile communication devices, and specific contexts where interruptions were identified to be a problem are presented. Some of the salient findings of the study include a generally complex situation with respect to interruptions that is impacted by technical, social and individual factors related to mobile communication, challenges related to managing personal and private communication on the same device, issues related to supporting distributed work in highly specialized care and how this contributes to interruptions, and a more in depth overview of specific contexts where interruptions are problematic than previous studies. Some theoretical perspectives on these issues are presented as well as implications for design.
Keywords: Ethnography; Mobile communication; Health care; Interruptions; Pervasive computing; Context-aware computing
SymbolChat: A flexible picture-based communication platform for users with intellectual disabilities BIBAKFull-Text 374-386
  Tuuli Keskinen; Tomi Heimonen; Markku Turunen; Juha-Pekka Rajaniemi; Sami Kauppinen
Persons with intellectual disabilities benefit from participating in the modern information society, especially the World Wide Web, social media and Internet-mediated communication services. Although several computer-based prototypes and commercial systems have been introduced for accessible in-person communication, currently few applications and services exist to support synchronous remote communication for this user group. We introduce SymbolChat, a software platform that supports the creation of multimodal communication applications utilizing picture-based instant messaging. End users and their support personnel can customize the input and output features of the application based on their individual needs and abilities. The interaction is based on touchscreen input and speech output using speech synthesis technology. The SymbolChat platform was developed together with the prospective end users and practitioners in the field of special needs care.
   We evaluated the prototype application in a field study with nine users with varying degrees of intellectual and other disabilities. The results clearly indicate that the participants were able to express themselves in spontaneous communication using a large-scale picture-based vocabulary (around 2000 symbols) even without prior training in the use of symbols. This finding was supported in the constructive feedback gathered from professionals working in the area. We also successfully applied methodology from other settings, such as child-computer interaction to evaluate interaction in this challenging context.
   Overall, the results show that social inclusion for people with intellectual disabilities can be improved with customizable communication tools. The implemented communication platform forms a solid basis for further improvements and new communication services. In addition, we found that users with motor impairments would greatly benefit from alternative input and output methods for symbol browsing and selection.
Keywords: Picture-based communication; Instant messaging; Augmentative and alternative communication; User-centered design
Shared online spreadsheets and hidden profiles: Technological effects on dyad decision strategy BIBAKFull-Text 387-397
  I. Fajardo; S. J. Payne
We report a study in which dyads use Instant Messaging to agree a preference among a set of three apartments. The information given to participants is partially overlapping, and contains a "hidden profile' (HP), such that a single apartment emerges as the best according to an unweighted sum of feature values only if dyad members pool information that is presented to only one of them. When dyads were additionally provided with a shared online spreadsheet, their decision strategy was more likely to be compensatory and relatively exhaustive, even if the distribution of importance among the cues in which the apartments vary meant that a "fast and frugal' heuristic such as take-the-best would be a rational strategy. This study shows the potential of classic experimental tasks, the HP task in particular, for understanding technological constraints on group decision making and signals the importance of understanding decision-making strategies, and the potential of fast and frugal heuristics, for informing the design of decision support systems.
Keywords: Group decision support system; Hidden profile task; Group decision strategy; Fast and frugal heuristic
Enhancing group awareness on the web: Prototype and experiments of sharing web page visitation information among teammates BIBAKFull-Text 398-408
  Qing Wang; Ya Li; Gaoqiang Zheng; Huiyou Chang
Group awareness is critical to improving the collaboration efficiency of a group, especially when teammates are geographically separated while working on the web. Previous studies have focused mainly on enhancing the awareness of the current working status of teammates, such as web pages being viewed, or other web activities, and they seldom take into account past working/browsing information, such as web pages visited or past web activities. However, the awareness of this kind of historical information can be useful for group collaboration. In this paper, we propose a novel approach to sharing web page visitation information among teammates. We present the design and implementation of our prototype, named Shared Browsing History. We then describe two user studies in which three groups with eight participants each used the prototype. The results of these studies show that our approach was effective in enhancing participants' group awareness and improved group collaborative efficiency in programming and software development tasks.
Keywords: Group awareness; Group collaboration; Browsing history; Web page visitation; Information sharing
Counting clicks and beeps: Exploring numerosity based haptic and audio PIN entry BIBAKFull-Text 409-422
  Andrea Bianchi; Ian Oakley; Dong Soo Kwon
Haptic and audio cues now appear commonly in computer interfaces, partially due to inherent advantages such as their support for eyes-free interaction. Their invisible, unobservable nature also makes them ideal candidates for security interfaces in which users have to enter secret information such as passwords. In particular, researchers have explored this idea through the design of PIN entry authentication systems based on multi-modal combinations of visual and non-visual content or on the recognition of small sets of unimodal haptic or audio stimuli. This paper highlights the benefits and performance limitations of these approaches and introduces an alternative based on unimodal audio or haptic temporal numerosity -- the ability to accurately and rapidly determine the number of cues presented in rapid temporal succession. In essence, in a numerosity interface, rather than recognizing distinct cues, users must count the number of times that a single cue occurs. In an iterative process of design and evaluation, three prototypes implementing this concept are presented and studies of their use reported. The results show the fastest PIN entry times and lowest error rates to be 8 s and 2%, figures that improve substantially on previous research. These results are attained while maintaining low levels of workload and substantial resistance to observation attack (as determined via camera attack security studies). In sum, this paper argues that unimodal audio and haptic numerosity is a valuable and relatively unexplored metaphor for non-visual input and demonstrates the validity of this claim in the demanding task of unobservable authentication systems.
Keywords: Human factors; Haptics and audio; Authentication; Mobile
A direct touch table-top display as a multi-user information kiosk: Comparing the usability of a single display groupware either by a single user or people cooperating as a group BIBAKFull-Text 423-437
  Mehmet Ilker Berkman; Adem Karahoca
This study aimed to investigate the usability of a direct touch table-top display (D3TD) application that was designed to be used as a multi-user information kiosk (MUIK). We examined its use by either a single person or multiple user groups to determine the effect of people cooperating as a group on its usability. We compared both groups' user performance and usability survey results. A one-way MANOVA of overall usability metrics emphasised a significant difference between the groups. Given the significance of the overall test, examining the univariate main effects revealed that the difference between the groups arose in the earlier system use stages due to differences in the success rate. There was no difference in the task completion time between the groups. Participants in the multiple user group achieved a higher task completion rate in the first phase and lower error rates in the following steps. However, the usability survey results did not reveal a significant difference between the groups. We observed that users working on the same individual task tended to help each other when working in a multi-user environment. These mutual aids occurred mostly in the earlier stages, influencing the users' performance. The results show that a D3TD has a potential to enhance usability in terms of effectiveness when deployed as a MUIK.
Keywords: Single display groupware (SDG); Direct touch table-top display (D3TD); Group interaction; Usability; Multi-user; Information kiosk

IWC 2012-11 Volume 24 Issue 6

Rating reflection on experience: A case study of teachers' and tutors' reflection around images BIBAKFull-Text 439-449
  Rowanne Fleck
Reflection on personal experience is described as a means to learn from experience, enable self-development and improve professional practice amongst other things. Recently there has been a move in HCI to explore new ways technology may support us in doing this. However, within this community there is little use made of existing literature to evaluate how well such tools support this reflection. In this paper we present a case study of the development of a 'levels of reflection' framework for the purposes of evaluating a wearable digital camera (SenseCam) to support teachers' and tutors' reflective practice. The framework enabled us to rate and compare reflection achieved by participants in different situations, and to explore the relationship between the ways images were used by participants and the level of reflection this led to, with implications for designing future SenseCam use to better support teachers' and tutors' reflection on experience. Beyond our particular case study, we suggest that the framework and associated methodological approach for rating reflection is of value to those within the HCI community interested in designing for reflection on experience. Rating reflection in this way can enable new tools or techniques for supporting reflection to be explored over time, across similar situations or with adaptations, and to build understandings of how reflection is being most effectively supported -- ultimately inspiring the design of future technologies by building up an understanding of the most effective ways of supporting reflection on experience.
Keywords: Rating framework; Reflection on experience; Reflective practice; Teacher training; SenseCam
Analytic review of usability evaluation in ISMAR BIBAKFull-Text 450-460
  Zhen Bai; Alan F. Blackwell
There has been a rapid increase in research evaluating usability of Augmented Reality (AR) systems in recent years. Although many different styles of evaluation are used, there is no clear consensus on the most relevant approaches. We report a review of papers published in International Symposium of Mixed and Augmented Reality (ISMAR) proceedings in the past decade, building on the previous work of Swan and Gabbard (2005). Firstly, we investigate the evaluation goal, measurement and method of ISMAR papers according to their usability research in four categories: performance, perception and cognition, collaboration and User Experience (UX). Secondly, we consider the balance of evaluation approaches with regard to empirical -- analytical, quantitative -- qualitative and participant demographics. Finally we identify potential emphases for usability study of AR systems in the future. These analyses provide a reference point for current evaluation techniques, trends and challenges, which benefit researchers intending to design, conduct and interpret usability evaluations for future AR systems.
Keywords: Augmented Reality; Usability evaluation; User experience; Collaboration
Evaluation of the quality of collaboration between the client and the therapist in phobia treatments BIBAKFull-Text 461-471
  Maja Wrzesien; Jean-Marie Burkhardt; Cristina Botella; Mariano Alcañiz
A growing number of empirical studies evaluate the influence of Mental Health (MH) technology on the clinical effectiveness, the therapeutic relationship (i.e., therapeutic alliance), and usability issues. However, to the authors' knowledge, no studies have yet been performed regarding the influence of technology on the therapeutic process in terms of collaboration. This study evaluates the quality of collaboration between the client and therapist in Augmented Reality Exposure Therapy (ARET) context and the traditional, In Vivo Exposure Therapy (IVET) context with the Therapeutic Collaborative Scale (TCS). Twenty participants received an intensive session of cognitive behavioral therapy in either a technology-mediated therapeutic context or in a traditional therapeutic context. The results indicate that both therapeutic conditions show high collaboration scores. However, the asymmetry of roles between the therapist and the client under both conditions were detected. Also, a greater level of distraction was observed for therapists in ARET, which affected the quality of the therapists' involvement in the therapeutic session. The implications of these results are discussed.
Keywords: Mental Health technologies; Collaboration; Augmented Reality
Grading in interaction design education using design practitioners' conceptions of process quality BIBAKFull-Text 472-481
  Mattias Arvola
The designed product is often assessed in interaction design education, but there are also courses that focus on learning the design process. It is then necessary to develop criteria for grading in such courses. To make a successful transfer from theory to practice, students also need to learn the criteria practitioners use, rather than the criteria that academically oriented teachers use. To do this, one approach is to align criteria with the conceptions practicing interaction designers have of process quality in design. Therefore, the research questions for this study are what those conceptions are, and how they can be utilized in grading criteria for interaction design projects in education. Interviews were made with 10 interaction designers. The interviews were qualitatively analyzed. The results demonstrate that practicing interaction designers conceptualize the quality of the design process in three ways: it is good if established methods are used and the design is managed within resource constraints, and within organizational and technological limitations, while also meeting stated objectives; it is even better if the design has a thought-through rationale; and ideally, the design should also be inspirational. These conceptions were transferred to points on a criteria-referenced grading scale which was used to develop course specific grading criteria. The criteria were evaluated in terms of comprehensibility and reliability. The evaluation showed that most of the students who also attended lectures understood the criteria. A high and significant covariation and a high level of agreement between the two teachers who graded the projects were shown. Further, the developed criteria should be generalizable to other process-centered interaction design courses and to assessment in other design disciplines.
Keywords: Interaction design education; Human -- computer interaction education; Design education; Process quality in design; Assessment; Grading
Towards building intelligent speech interfaces through the use of more flexible, robust and natural dialogue management solutions BIBAKFull-Text 482-498
  Fernando Fernández-Martánez; J. Ferreiros; J. M. Lucas-Cuesta; J. M. Montero-Martánez; R. San-Segundo; R. Córdoba
In this paper a Bayesian Networks-based solution for dialogue modelling is presented. This solution is combined with carefully designed contextual information handling strategies. With the purpose of validating these solutions, and introducing a spoken dialogue system for controlling a Hi-Fi audio system as the selected prototype, a real-user evaluation has been conducted. Two different versions of the prototype are compared. Each version corresponds to a different implementation of the algorithm for the management of the actuation order, the algorithm for deciding the proper order to carry out the actions required by the user. The evaluation is carried out in terms of a battery of both subjective and objective metrics collected from speakers interacting with the Hi-Fi audio box through predefined scenarios. Defined metrics have been specifically adapted to measure: first, the usefulness and the actual relevance of the proposed solutions, and, secondly, their joint performance through their intelligent combination mainly measured as the level achieved with regard to the user satisfaction. A thorough and comprehensive study of the main differences between both approaches is presented. Two-way analysis of variance (ANOVA) tests are also included to measure the effects of both: the system used and the type of scenario factors, simultaneously. Finally, the effect of bringing this flexibility, robustness and naturalness into our home dialogue system is also analyzed through the results obtained. These results show that the intelligence of our speech interface has been well perceived, highlighting its excellent ease of use and its good acceptance by users, therefore validating the approached dialogue management solutions and demonstrating that a more natural, flexible and robust dialogue is possible thanks to them.
Keywords: Spoken dialogue systems; Mixed initiative; Bayesian Networks; Contextual information; Usability; Electronic devices control