Showing papers in "International Journal of Human-computer Studies \/ International Journal of Man-machine Studies in 2011"

The influence of intrinsic and extrinsic motivation on individuals' knowledge sharing behavior

Abstract: A major challenge in knowledge management involves motivating people to share knowledge with others. The objective of this study is to deepen our understanding of how to influence an individual's tendency to engage in knowledge sharing behavior in a team setting. Specifically, we investigate the effects of intrinsic motivation (altruism) and extrinsic motivation (economic reward, reputation feedback and reciprocity) on knowledge sharing (number of ideas generated, idea usefulness, idea creativity and meeting satisfaction) in a group meeting. Results of our experiment show that a knowledge management system with built-in reputation feedback is crucial to support successful knowledge sharing.

Understanding the new digital divide-A typology of Internet users in Europe

Abstract: The purpose of this study is to better understand the digital divide by identifying the variety of ways in which people in Europe use the Internet. First, by using cluster analysis on survey data (N=12,666/age: 16-74 years) from Eurostat on Internet usage in Norway, Sweden, Austria, the UK, and Spain, we identified five user types: Non-Users (42%), Sporadic Users (18%), Instrumental Users (18%), Entertainment Users (10%), and Advanced Users (12%). These user types differ in their distributions over country, age, access, household members, and gender. An alarming finding is that 60% of the population was found to be either Non-Users or Sporadic Users, which reflects a large digital divide in Europe. Second, we conducted a logistic regression to identify the predictors for different user types. We found on a cross-national level that age and Internet access are the most salient predictors, whereas gender and household seems to be less relevant. However, the amount of variance explained differs between countries. We also suggested a future increase in the digital divide between the identified user types-a user type divide. The user typology and the identified predictors might help researchers, practitioners, and decision makers to better understand Internet users and the multi-complex variations among individuals and countries. This knowledge will also serve as a means to understand the digital divide by providing a more nuanced perspective on Europeans' unequal usage of the Internet and participation in an increasingly digital society.

I'm home: Defining and evaluating a gesture set for smart-home control

Abstract: Mobile phones seem to present the perfect user interface for interacting with smart environments, e.g. smart-home systems, as they are nowadays ubiquitous and equipped with an increasing amount of sensors and interface components, such as multi-touch screens. After giving an overview on related work this paper presents the adapted design methodology proposed by Wobbrock et al. (2009) for the development of a gesture-based user interface to a smart-home system. The findings for the new domain, device and gesture space are presented and compared to findings by Wobbrock et al. (2009) . Three additional steps are described: A small pre-test survey, a mapping and a memory test and a performance test of the implemented system. This paper shows the adaptability of the approach described by Wobbrock et al. (2009) for three-dimensional gestures in the smart-home domain. Elicited gestures are described and a first implementation of a user interface based on these gestures is presented.

Understanding how children understand robots: Perceived animism in child-robot interaction

Abstract: Centuries ago, the existence of life was explained by the presence of a soul (Tylor, 1871). Known as animism, this term was re-defined in the 1970s by Piaget as young children's beliefs that inanimate objects are capable of actions and have life-like qualities. With the development of robots in the 21st century, researchers have begun examining whether animism is apparent in children's impressions of robots. The purpose of this study was to use a model of knowledge structures, or schemata, to examine whether children attribute human qualities of cognition, affect, and behavior to a robot. An experiment was set up at a science center located in a major Western Canadian city, and visitors to the center were invited to participate. A total of 198 children ages 5-16 years (M=8.18 years) with an approximate even number of boys and girls were included. Children completed a semi-structured interview after observing a robot, a small 5 degree of freedom robot arm, perform a block stacking task. Answers to the nine questions about the robot were scored according to whether they referenced humanistic qualities. Results from frequency and content analyses suggest that a significant proportion of children ascribe cognitive, behavioral, and especially affective, characteristics to robots.

A virtual reality system for the treatment of stress-related disorders: A preliminary analysis of efficacy compared to a standard cognitive behavioral program

Abstract: This paper presents preliminary efficacy data in a controlled study of the use of a virtual reality (VR) system for treating stress-related disorders (Post-Traumatic Stress Disorder, or PTSD; Pathological Grief, or PG; and Adjustment Disorders, or AD). ''EMMA's World'' is a VR application in which patients can explore negative experiences to the degree required for their specific therapeutic needs. To accomplish therapeutic goals, a series of virtual elements is customized to be meaningful to the user; the elements contain the fundamental emotional components that the person must confront. Thirty-nine participants diagnosed with PTSD (N=10), PG (N=16), and AD (N=13) were randomly assigned to a standard cognitive-behavioral program (CBT) (N=20) or a CBT program driven by EMMA's World (N=19). Participants were assessed before and after treatment. Measurements related to anxiety, depression and other emotions, maladjustment and interference were applied. Results indicate that CBT with EMMA's World was as effective as the standard CBT program for the treatment of these disorders, and the statistically significant differences (depression, relaxation intensity and social area interference) were in favor of EMMA's World. We expect VR to provide a positive alternative that will draw in clients who do not seek traditional forms of treatment.

Factors affecting perception of information security and their impacts on IT adoption and security practices

Abstract: The gap between the perceived security of an information system and its real security level can influence people' decisions and behavior. The objective of this study is to find effective ways to adjust people's perception of information security, in order to enhance their intention to adopt IT appliances and compliance to security practices. Two separate experiments were conducted. In experiment I, 64 participants were asked to transfer money through an e-banking system. Their intention to adopt e-banking was measured by a questionnaire. In experiment II, 64 participants were asked to register on an online forum. Their subjective intention to create a strong password was measured by a questionnaire, and the objective strength of the passwords they created was calculated. Results of the ANOVA and the path models derived from the path analysis indicated that people's adoption intention, such as their intention to adopt e-banking, can be enhanced by changing their perceived Knowledge, Controllability and Awareness, while changing the perceived Controllability is most effective. The results also indicated that people's compliance to security practices, such as setting strong passwords for IT systems, can be enhanced by changing their perceived Knowledge, Severity and Possibility, while changing their perceived Knowledge and Severity is most effective. Implications for further research and practice were also discussed.

The notion of overview in information visualization

Abstract: Overview is a frequently used notion and design goal in information-visualization research and practice. However, it is difficult to find a consensus on what an overview is and to appreciate its relation to how users understand and navigate an information space. We review papers that use the notion of overview and develop a model. The model highlights the awareness that makes up an overview, the process by which users acquire it, the usefulness of overviews, and the role of user-interface components in developing an overview. We discuss the model in relation to classic readings in information visualization and use it to generate recommendations for future research.

Air pointing: Design and evaluation of spatial target acquisition with and without visual feedback

Abstract: Sensing technologies such as inertia tracking and computer vision enable spatial interactions where users make selections by 'air pointing': moving a limb, finger, or device to a specific spatial region. In addition of expanding the vocabulary of possible interactions available, air pointing brings the potential benefit of enabling 'eyes-free' interactions, where users rely on proprioception and kinaesthesia rather than vision. This paper explores the design space for air pointing interactions, and presents tangible results in the form of a framework that helps designers understand input dimensions and resulting interaction qualities. The framework provides a set of fundamental concepts that aid in thinking about the air pointing domain, in characterizing and comparing existing solutions, and in evaluating novel techniques. We carry out an initial investigation to demonstrate the concepts of the framework by designing and comparing three air pointing techniques: one based on small angular 'raycasting' movements, one on large movements across a 2D plane, and one on movements in a 3D volume. Results show that large movements on the 2D plane are both rapid (selection times under 1s) and accurate, even without visual feedback. Raycasting is rapid but inaccurate, and the 3D volume is expressive but slow, inaccurate, and effortful. Many other findings emerge, such as selection point 'drift' in the absence of feedback. These results and the organising framework provide a foundation for innovation and understanding of air pointing interaction.

Modeling of operators' emotion and task performance in a virtual driving environment

Abstract: Emotional human-computer interactions are attracting increasing interest with the improvement in the available technology. Through presenting affective stimuli and empathic communication, computer agents are able to adjust to users' emotional states. As a result, users may produce better task performance. Existing studies have mainly focused on the effect of only a few basic emotions, such as happiness and frustration, on human performance. Furthermore, most research explored this issue from the psychological perspective. This paper presents an emotion and performance relation model in the context of vehicle driving. This general emotion-performance model is constructed on an arousal-valence plane and is not limited to basic emotions. Fifteen paid participants took part in two driving simulation experiments that induced 115 pairs of emotion-performance sample. These samples revealed the following: (1) driving performance has a downward U-shaped relationship with both intensities of arousal and valence. It deteriorates at extreme arousal and valence. (2) Optimal driving performance, corresponding to the appropriate emotional state, matches the ''sweet spot'' phenomenon of the engagement psychology. (3) Arousal and valence are not perfectly independent across the entire 2-D emotion plane. Extreme valence is likely to stimulate a high level of arousal, which, in turn, deteriorates task performance. The emotion-performance relation model proposed in the paper is useful in designing emotion-aware intelligent systems to predict and prevent task performance degradation at an early stage and throughout the human-computer interactions.

Reliability, validity, and sensitivity of a single-item measure of online store usability

Abstract: In an experimental study, we examined the validity and reliability of a single-item measure for customers' assessment of online store usability. Each of the 378 participants visited two out of 35 online stores and performed three shopping related tasks. Usability was rated using a single-item and an eight-item measure. In addition to trust in the online store and aesthetics, we also measured the participant's intention to buy. Results from factor analysis and the correction for attenuation formula revealed an adequate reliability of the single-item measure. Positive correlations with both trust and aesthetics supported the convergent validity of the single-item measure for usability. The positive correlation between the single-item and the intention to buy demonstrated the high predictive validity of this measure. Finally, results support the sensitivity of the single-item measure to differentiate between the usability for each online store.

Psychological needs and virtual worlds: Case Second Life

Abstract: The most advanced contemporary virtual worlds provide their users with a possibility for living versatile virtual lives together with other users. A growing number of users worldwide are utilizing this possibility. The aim of this research was to study active virtual world users' satisfaction of psychological needs both inworld and outworld. A global online survey for the users of Second Life was constructed based on a model of ten psychological needs. The results based on 258 responses indicated that self-esteem, autonomy and physical thriving were the most highly satisfied needs inworld. Furthermore, the results indicated that autonomy, physical thriving, and money-luxury were needs, which were satisfied to a significantly larger extent in the virtual world than in the users' real lives (when not using a computer). On the other hand, the needs for competence, relatedness, security, and popularity-influence were more extensively satisfied in the users' daily lives than when in Second Life. The qualitative findings highlighted relatedness needs as motivations for Second Life usage and revealed five central themes in the motivations for Second Life usage: Second Life as self-therapy, as a source of instant pleasures, as liberation from social norms, as a tool for self-expression, and as exploration and novelty. In all, the findings suggest that the use of advanced virtual worlds is driven by a variety of different psychological needs. Virtual world usage is also related to need satisfaction in the users' lives outside the virtual world.

Affect prediction from physiological measures via visual stimuli

Abstract: This study aims to predict different affective states via physiological measures with three types of computational models. An experiment was designed to elicit affective states with standardized affective pictures when multiple physiological signals were measured. Three data mining methods (i.e., decision rules, k-nearest neighbours, and decomposition tree) based on the rough set technique were then applied to construct prediction models from the extracted physiological features. We created three types of prediction models, i.e., gender-specific (male vs. female), culture-specific (Chinese vs. Indian vs. Western), and general models (participants with different genders and cultures as samples), and direct comparisons were made among these models. The best average prediction accuracies in terms of the F"1 measures (the harmonic mean of precision and recall) were 60.2%, 64.9%, 63.5% for the general models with 14, 21, and 42 samples, 78.0% for the female models, 75.1% for the male models, 72.0% for the Chinese models, 73.0% for the Indian models, and 76.5% for the Western models, respectively. These results suggested that the specific models performed better than did the general models.

Lovers' box: Designing for reflection within romantic relationships

Abstract: We present the Lovers' box, a digital artefact designed to engage romantic couples in reflections on their relationship. By adopting perspectives from social psychology and interaction design, the work examines the role of reflection through the use of a non-traditional digital artefact that acts as a site for enduring attachments of personal emotional significance. To this end, we respond to previous research work on reflection through design, in the development of four Lovers' boxes whose purposes and meanings are completed through reflections both by romantic couples and their integration in everyday lives. A field study was conducted involving five couples in new relationships who were asked to exchange video messages (co-created with a digital media artist) using the Lovers' box over a period of five weeks. Our findings demonstrated: (1) that the creation, exchange and display of messages embedded in the digital artefact served as both mirrors and sources for reflection concerning couples' relationships; (2) the rich manner in which the Lovers' box became meaningful to participants, as they perceived it as keepsake or digital storybook of their meaningful experiences, experienced it as an enjoyable shared hobby with their partner and saw it as providing them a snapshot into the beloved person's mind and thoughts; and (3) how the potential for new castings of digital artefacts might support our personal and emotional lives.

Aesthetics and usability of in-vehicle navigation displays

Abstract: This research evaluates the aesthetics and usability of various in-vehicle electronic navigation map configurations. Study 1 adapted the aesthetics scale (Lavie and Tractinsky, 2004) to accommodate evaluations of map displays. Study 2 examined map displays that vary in the amount of data presented, their abstraction level and color schema, using objective and subjective usability measures. Maps with minimal detail produced best performances and highest evaluations. Abstractions were found to be advantageous when combined with reduced amount of detail and specific color schemas. Moderate abstractions were sufficient for obtaining the desired benefits. The color schema mainly affected the objective measures, pointing to the importance of good contrast between the cursor and the map colors. Study 3 further examined map schemas. Color schemas again had no effect on the perceptions of aesthetics and usability. Overall, similar results and high correlations were found for the perceived aesthetics and usability scales, indicating the connection between perceived aesthetics and usability. Lower correlations were found between the actual usability (performance) and the aesthetics scale. Finally, users' usability evaluations were not always in line with their actual performance, pointing to the importance of using objective usability measures.

MiRA-Mixed Reality Agents

Abstract: In recent years, an increasing number of Mixed Reality (MR) applications have been developed using agent technology - both for the underlying software and as an interface metaphor However, no unifying field or theory currently exists that can act as a common frame of reference for these varied works As a result, much duplication of research is evidenced in the literature This paper seeks to fill this important gap by outlining ''for the first time'' a formal field of research that has hitherto gone unacknowledged, namely the field of Mixed Reality Agents (MiRAs), which are defined as agents embodied in a Mixed Reality environment Based on this definition, a taxonomy is offered that classifies MiRAs along three axes: agency, based on the weak and strong notions outlined by Wooldridge and Jennings (1995); corporeal presence, which describes the degree of virtual or physical representation (body) of a MiRA; and interactive capacity, which characterises its ability to sense and act on the virtual and physical environment Furthermore, this paper offers the first comprehensive survey of the state-of-the-art of MiRA research and places each project within the proposed taxonomy Finally, common trends and future directions for MiRA research are discussed By defining Mixed Reality Agents as a formal field, establishing a common taxonomy, and retrospectively placing existing MiRA projects within it, future researchers can effectively position their research within this landscape, thereby avoiding duplication and fostering reuse and interoperability

An empirical investigation into the design of auditory cues to enhance computer program comprehension

Abstract: Decades of research have led to notable improvements in the representations used to aid human comprehension of computer programs. Much of this research has focused on visual representations, which leaves open the question of how best to design auditory representations of computer programs. While this question has particular relevance for visually impaired programmers, sighted programmers might also benefit from enhanced auditory representations of their programs. In order to investigate this question empirically, first, we introduce artifact encoding, a novel approach to rigorously measuring the comprehensibility of auditory representations of computer programs. Using this approach as a foundation, we present an experimental study that compared the comprehensibility of two alternative auditory program representations: one with lexical scoping cues that convey the nesting level of program statements, and another without such scoping cues. The results of our first experiment validate both artifact encoding and the scoping cues we used. To see whether auditory cues validated through our paradigm can aid program comprehension in a realistic task scenario, we experimentally compared programmers' ability to debug programs using three alternative environments: (1) an auditory execution environment with our empirically derived auditory cues; (2) an auditory execution environment with the current state-of-the-art auditory cues generated by a screen reader running on top of Microsoft Visual Studio; and (3) a visual version of the execution environment. The results of our second experiment showed that our comprehensible auditory cues are significantly better than the state-of-the-art, affording human performance approaching the effectiveness of visual representations within the statistical margin of error. This research contributes a novel methodology and foundational empirical data that can guide the design of effective auditory representations of computer programs.

A politeness effect in learning with web-based intelligent tutors

Abstract: College students learned to solve chemistry stoichiometry problems with a web-based intelligent tutor that provided hints and feedback, using either polite or direct language. There was a pattern in which students with low prior knowledge of chemistry performed better on subsequent problem-solving tests if they learned from the polite tutor rather than the direct tutor (d=.78 on an immediate test, d=.51 on a delayed test), whereas students with high prior knowledge showed the reverse trend (d=-.47 for an immediate test; d=-.13 for a delayed test). These results point to a boundary condition for the politeness principle-the idea that people learn more deeply when words are in polite style. At least for low-knowledge learners, the results are consistent with social agency theory-the idea that social cues, such as politeness, can prime learners to accept a web-based tutor as a social partner and therefore try harder to make sense of the tutor's messages.

Pushing personhood into place: Situating media in rural knowledge in Africa

Abstract: Designing interactions with technologies that are compatible with rural wisdom and skills can help to digitally enfranchise rural people and, thus, contribute to community cohesion in the face of Africa's urbanization. Oral information has been integral to rural identity and livelihood in Africa for generations. However, the use of technology can inadvertently displace the knowledge of communities with practices that differ from the knowledge traditions in which technology is designed. We propose that devices that are sensitive to users' locations, combined with platforms for social networking and user-generated content, offer intriguing opportunities for rural communities to extend their knowledge practices digitally. In this paper we present insights on the way rural people of the Herero tribe manage information spatially and temporally during some of our design activities in Namibia. We generated these insights from ethnography and detailed analysis of interactions with media in our ongoing Ethnographic Action Research. Rural participants had not depicted their wisdom graphically by photography or video before, rarely use writing materials and some cannot read. Thus, we gathered 30h of observer-and participant-recorded video and participants' interpretations and interactions with thumbnail photos from video, photography and paper. We describe insights into verbal and bodily interactions and relationships between bodies, movements, settings, knowledge and identity. These findings have made us more sensitive to local experiences of locations and more aware of assumptions about space and time embedded in locative media. As a result, we have started to adopt an approach that emphasizes connectors rather than points and social-relational and topokinetic rather than topographic spaces. In the final section of the paper we discuss applying this approach in design by responding to the ways that participants use social relationships to orient information and use voice, gesture and movement to incorporate locations into this ''dialogic''. In conclusion we outline why we hope our reflections will inspire others to examine the spatial, temporal and social affordances of technologies within the bonds of rural, and other, communities.

What does it mean to be good at using a mobile device? An investigation of three levels of experience and skill

Abstract: An increasing number of computer users lack formal training in operating their devices. These daily users cannot be described as novices or experts within the predominant view of expertise. In order to describe and better understand this type of self-taught intermediate level of skill, 10 casual users of a high-end smartphone series were compared to 10 novices and 4 professionals (help desk personnel) in their learning histories, task performance, and cognitive outcomes. Our study suggests that this type of self-taught intermediate level of skill is device-specific. Experienced users (casual users and experts) exhibited superior performance for representative tasks. This is mainly attributable to faster navigation and better knowledge of interface terminology, not to deeper conceptual representation of the problems. Interviews suggest that this skill is the consequence of routine use and three recurring learning events: familiarization, following of media, and ad hoc problem-solving situations. We conclude by discussing why intermediate levels of skill deserve more attention in HCI research.

Investigating paper vs. screen in real-life hospital workflows: Performance contradicts perceived superiority of paper in the user experience

Abstract: Introduction: All hospitals in the province of Styria (Austria) are well equipped with sophisticated Information Technology, which provides all-encompassing on-screen patient information. Previous research made on the theoretical properties, advantages and disadvantages, of reading from paper vs. reading from a screen has resulted in the assumption that reading from a screen is slower, less accurate and more tiring. However, recent flat screen technology, especially on the basis of LCD, is of such high quality that obviously this assumption should now be challenged. As the electronic storage and presentation of information has many advantages in addition to a faster transfer and processing of the information, the usage of electronic screens in clinics should outperform the traditional hardcopy in both execution and preference ratings. This study took part in a County hospital Styria, Austria, with 111 medical professionals, working in a real-life setting. They were each asked to read original and authentic diagnosis reports, a gynecological report and an internal medical document, on both screen and paper in a randomly assigned order. Reading comprehension was measured by the Chunked Reading Test, and speed and accuracy of reading performance was quantified. In order to get a full understanding of the clinicians' preferences, subjective ratings were also collected. Results: Wilcoxon Signed Rank Tests showed no significant differences on reading performance between paper vs. screen. However, medical professionals showed a significant (90%) preference for reading from paper. Despite the high quality and the benefits of electronic media, paper still has some qualities which cannot provided electronically do date.

Design and evaluation of freehand menu selection interfaces using tilt and pinch gestures

Abstract: Freehand gestural interaction, in which the user's hands move in mid-air to provide input, has been of interest to researchers, but freehand menu selection interfaces have been under-investigated so far. Freehand menu selection is inherently difficult, especially with increasing menu breadth (i.e., the number of items), largely because moving hands in free space cannot achieve precision as high as physical input devices such as mouse and stylus. We have designed a novel menu selection interface called the rapMenu (Ni et al., 2008), which is controlled by wrist tilt and multiple pinch gestures, and takes advantage of the multiple discrete gesture inputs to reduce the required precision of the user hand movements. In this article, we first review the visual design and behavior of the rapMenu technique, as well as related design issues and its potential advantages. In the second part, we present two studies of the rapMenu in order to further investigate the strengths and limitations of the design principle. In the first study, we compared the rapMenu to the extensively studied tilt menu technique (Rahman et al., 2009). Our results revealed that the rapMenu outperforms the tilt menu as menu breadth increases. In the second study, we investigated how the rapMenu affords the opportunity of eyes-free selection and users' transition from novice to expert. We found that within 10min of practice, eyes-free selection with rapMenu has competitive speed and accuracy with the visual rapMenu and the tilt menu. Finally, we discuss design variations that use other axes of wrist movement and adopt alternative auditory feedback.

Understanding human values in adopting new technology-A case study and methodological discussion

Abstract: This paper proposes a method for understanding and modelling human values in the evaluation of new technology in social settings, and analyses the validity of the proposed method in a specific use case. The method, which is based on the Schwartz universal model of human values adopted from social psychology research, is used in the context of value analysis of the adoption of a technology-supported attendance control system in a primary school. The results are based on an evaluation of a 14-week trial where two classes of elementary school children used an attendance control system that was implemented using networked technology components, including smart cards, NFC-enabled mobile phones and card readers, a web portal, and SMS messaging. The findings from the trial are analysed from the viewpoint of three end-user groups, namely children, parents, and teachers.

A saunter down memory lane: Digital reflection on personal mementos

Abstract: We all collect personal mementos, treasured objects that remind us about our past. We also remember significant people and places from our past. A key way that we reflect on our identity is through collecting, organizing and talking to others about such personal mementos, places and people. However, most work on mementos has focused on physical objects rather than their digital representations. And when digital archives have been examined these have been found to be underexploited. We, therefore, implemented and evaluated a new class of digital memory application, MemoryLane, that is designed on the basis of prior research into memory and reminiscence. MemoryLane allows people to capture, actively organize and reflect on digital representations of mementos relating to people, places and objects. Users can also annotate captured mementos with spoken or textual narratives. User feedback provides new information about the nature of digital reminiscing and reflection. Our 31 persons evaluation showed that people were active in organizing and reflecting on these personal digital collections. As we expected, most mementos centered around familiar home objects, although mementos relating to people tended to be regarded as most important and to evoke stronger emotions. Participants also recorded many spoken narratives about mementos, but these spoken reflections were unpopular on playback. We discuss the theoretical and design implications of our work.

The role of Depth and Gestalt cues in information-rich virtual environments

Abstract: Managing the layout of multi-dimensional visualizations is a crucial concern for the development of effective visual analytic interfaces. In these environments, heterogeneous and multi-dimensional information must be structured and combined into data representations that demand low cognitive resources but yield accurate mental models and insights. In this paper, we use Information-Rich Virtual Environments (IRVE) to articulate crucial tradeoffs in the use of Depth and Gestalt cues in text label layouts. We present a design space and evaluation methodology to explore the usability effects of these tradeoffs and collect results from a series of user studies. These lessons are posed as a set of design guidelines to aid developers of new, advantageous interfaces and specifications.

Situating digital storytelling within African communities

Abstract: We reflect on the methods, activities and perspectives we used to situate digital storytelling in two rural African communities in South Africa and Kenya. We demonstrate how in-depth ethnography in a village in the Eastern Cape of South Africa and a design workshop involving participants from that village allowed us to design a prototype mobile digital storytelling system suited to the needs of rural, oral users. By leveraging our prototype as a probe and observing villagers using it in two villages in South Africa and Kenya, we uncovered implications for situating digital storytelling within those communities. Finally, we distil observations relevant to localizing storytelling and their implications for transferring design into a different community.

Design of human-centric adaptive multimodal interfaces

Abstract: Multimodal interfaces have attracted more and more attention. Most researches focus on each interaction mode independently and then fuse information at the application level. Recently, several frameworks and models have been proposed to support the design and development of multimodal interfaces. However, it is challenging to provide automatic modality adaptation in multimodal interfaces. Existing approaches are using rule-based specifications to define the adaptation of input/output modalities. Rule-based specifications have the problems of completeness and coherence. Distinct from previous work, this paper presents a novel approach that quantifies the user preference of each modality and considers the adaptation as an optimization issue that searches for a set of input/output modalities matching user's preference. Our approach applies a cross-layer design, which considers the adaptation from the perspectives of the interaction context, available system resources, and QoS requirements. Furthermore, our approach supports human-centric adaptation. A user can report the preference of a modality so that selected modalities fit user's personal needs. An optimal solution and a heuristic algorithm have been developed to automatically select an appropriate set of modality combinations under a specific situation. We have designed a framework based on the heuristic algorithm and existing ontology, and applied the framework to conduct a utility evaluation, in which we have employed a within-subject experiment. Fifty participants were invited to go through three scenarios and compare automatically selected modalities with randomly selected modalities. The results from the experiment show that users perceived the automatically selected modalities as appropriate and satisfactory.

See-through techniques for referential awareness in collaborative virtual reality

Abstract: Multi-user virtual reality systems enable natural collaboration in shared virtual worlds. Users can talk to each other, gesture and point into the virtual scenery as if it were real. As in reality, referring to objects by pointing results often in a situation whereon objects are occluded from the other users' viewpoints. While in reality this problem can only be solved by adapting the viewing position, specialized individual views of the shared virtual scene enable various other solutions. As one such solution we propose show-through techniques to make sure that the objects one is pointing to can always be seen by others. We first study the impact of such augmented viewing techniques on the spatial understanding of the scene, the rapidity of mutual information exchange as well as the proxemic behavior of users. To this end we conducted a user study in a co-located stereoscopic multi-user setup. Our study revealed advantages for show-through techniques in terms of comfort, user acceptance and compliance to social protocols while spatial understanding and mutual information exchange is retained. Motivated by these results we further analyze whether show-through techniques may also be beneficial in distributed virtual environments. We investigated a distributed setup for two users, each participant having its own display screen and a minimalist avatar representation for each participant. In such a configuration there is a lack of mutual awareness, which hinders the understanding of each other's pointing gestures and decreases the relevance of social protocols in terms of proxemic behavior. Nevertheless, we found that show-through techniques can improve collaborative interaction tasks even in such situations.

Remembering today tomorrow: Exploring the human-centred design of digital mementos

Abstract: This paper describes two-part research exploring the context for and human-centred design of 'digital mementos', as an example of technology for reflection on personal experience (in this case, autobiographical memories). Field studies into families' use of physical and digital objects for remembering provided a rich understanding of associated user needs and human values, and suggested properties for 'digital mementos' such as being 'not like work', discoverable and fun. In a subsequent design study, artefacts were devised to express these features and develop the understanding of needs and values further via discussion with groups of potential 'users'. 'Critical artefacts' (the products of Critical Design) were used to enable participants to envisage broader possibilities for social practices and applications of technology in the context of personal remembering, and thus to engage in the design of novel devices and systems relevant to their lives. Reflection was a common theme in the work, being what the digital mementos were designed to afford and the mechanism by which the design activity progressed. Ideas for digital mementos formed the output of this research and expressed the designer's and researcher's understanding of participants' practices and needs, and the human values that underlie them and, in doing so, suggest devices and systems that go beyond usability to support a broader conception of human activity.

Investigating the affective quality of interactivity by motion feedback in mobile touchscreen user interfaces

Abstract: Emotion is a key aspect of user experience. To design a user interface for positive emotional experience, the affective quality of the user interface needs to be carefully considered. A major factor of affective quality in today's user interface for digital media is interactivity, in which motion feedback plays a significant role as an element. This role of motion feedback is particularly evident in touchscreen user interfaces that have been adopted rapidly in mobile devices. This paper presents two empirical studies performed to increase our understanding of motion feedback in terms of affective quality in mobile touchscreen user interfaces. In the first study, the relationships between three general motion properties and a selected set of affective qualities are examined. The results of this study provide a guideline for the design of motion feedback in existing mobile touchscreen user interfaces. The second study explores a new dimension of interactivity that is the Weight factor of Laban's Effort system. To experiment the Weight factor in a mobile touchscreen user interface, a pressure sensitive prototype was developed to recognize the amount of force applied by the user's finger action. With this prototype, the effects of implementing pressure requirements on four different types of user interfaces were examined. Results show that implementing the Weight factor can significantly influence the affective quality and complement the physical feel of a user interface. The issues to consider for effective implementation are also discussed.

Object interaction detection using hand posture cues in an office setting

Abstract: Activity recognition plays a key role in providing information for context-aware applications. When attempting to model activities, some researchers have looked towards Activity Theory, which theorizes that activities have objectives and are accomplished through interactions with tools and objects. The goal of this paper is to determine if hand posture can be used as a cue to determine the types of interactions a user has with objects in a desk/office environment. Furthermore, we wish to determine if hand posture is user-independent across all users when interacting with the same objects in a natural manner. Our experiments indicate that (a) hand posture can be used to determine object interaction, with accuracy rates around 97%, and (b) hand posture is dependent upon the individual user when users are allowed to interact with objects as they would naturally.