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IJHCS Tables of Contents: 505152535455565758596061626364656667686970

International Journal of Human-Computer Studies 60

Editors:B. R. Gaines
Dates:2004
Volume:60
Publisher:Elsevier Science Publishers
Standard No:ISSN 0020-7373; TA 167 A1 I5
Papers:34
Links:Table of Contents
  1. IJHCS 2004 Volume 60 Issue 1
  2. IJHCS 2004 Volume 60 Issue 2
  3. IJHCS 2004 Volume 60 Issue 3
  4. IJHCS 2004 Volume 60 Issue 4
  5. IJHCS 2004 Volume 60 Issue 5/6

IJHCS 2004 Volume 60 Issue 1

ARTICLE

Bringing virtual reality for commercial Web sites BIBA 1-15
  G. Bhatt
In today's competitive environment, a growing number of firms are establishing their presence in the market space. Even though the potential of the Internet in shaping business strategies has been widely acknowledged, firms in an array of industries are still struggling to attract customers through their Web sites. Based on Steuer's (J. Commun. 42(4) (1992) 73) and Rheingold (The Virtual Community, ACM/Addison-Wesley, Reading, MA, 1993) arguments on perceptual experience in the virtual space, we present a theoretical framework that highlights the relative importance of interactivity, immersion, and connectivity for attracting customers through a Web site. Interactivity has been measured through the speed of interactivity, range of interactivity, and significance. Immersion has been measured through the breadth of immersion and depth of immersion. Connectivity has been measured through the scope of connectivity. Through an experimental study, the features of amazon.com, ebay.com, schwab.com, and victoriasecret.com have been analysed with respect to interactivity, immersion, and connectivity. We argue that in order to attract customers through their Web sites, dot-coms are required to balance a trade-off between interactivity, immersion, and connectively, depending on their business objectives.
Learning ontologies from natural language texts BIBA 17-63
  Mehrnoush Shamsfard; Ahmad Abdollahzadeh Barforoush
Research on ontology is becoming increasingly widespread in the computer science community. The major problems in building ontologies are the bottleneck of knowledge acquisition and time-consuming construction of various ontologies for various domains/applications. Meanwhile moving toward automation of ontology construction is a solution.
   We proposed an automatic ontology building approach. In this approach, the system starts from a small ontology kernel and constructs the ontology through text understanding automatically. The kernel contains the primitive concepts, relations and operators to build an ontology. The features of our proposed model are being domain/application independent, building ontologies upon a small primary kernel, learning words, concepts, taxonomic and non-taxonomic relations and axioms and applying a symbolic, hybrid ontology learning approach consisting of logical, linguistic based, template driven and semantic analysis methods.
   Hasti is an ongoing project to implement and test the automatic ontology building approach. It extracts lexical and ontological knowledge from Persian (Farsi) texts.
   In this paper, at first, we will describe some ontology engineering problems, which motivated our approach. In the next sections, after a brief description of Hasti, its features and its architecture, we will discuss its components in detail. In each part, the learning algorithms will be described. Then some experimental results will be discussed and at last, we will have an overview of related works and will introduce a general framework to compare ontology learning systems and will compare Hasti with related works according to the framework.
The collective control of perceptions: constructing order from conflict BIBA 65-99
  Kent McClelland
This article offers a new perspective on sociological theory, based on psychological insights from Perceptual Control Theory. After describing this cybernetic model of goal-directed behavior and reviewing its empirical support, I present results from computer simulations applying the model to the social interactions of elementary control agents. My key finding is that agents controlling their own perceptions of a single environmental variable can stabilize it even when their intentions conflict. The concluding section discusses implications of this model of collective control processes for the sources of order, conflict, continuity, and change in social life.
Using task analysis to improve usability of fatigue modelling software BIBA 101-115
  Michael Paradowski; Adam Fletcher
The design of any interactive computer system requires consideration of both humans and machines. Software usability is one aspect of human-computer interaction that can benefit from knowledge of the user and their tasks. One set of methods for determining whether an application enables users to achieve their predetermined goals effectively and efficiently is task analysis. In the present study, a task analysis was applied to the graphical user interface of fatigue modelling software used in industry. The task analysis procedure allowed areas of usability improvement to be identified and then addressed with alternate interface prototypes. The present method of task analysis illustrates a practical and efficient way for software designers to improve software usability, user effectiveness and satisfaction, by involving users in the design process.
When mental models go wrong: co-occurrences in dynamic, critical systems BIBA 117-128
  Denis Besnard; David Greathead; Gordon Baxter
This paper highlights a psychological phenomenon affecting the accuracy of mental models. It occurs when two consecutive events happen as expected by an operator. Typically, such a situation reinforces the confidence in one's mental model. However, consecutive events can happen as a random co-occurrence, for reasons that actually differ from the ones believed by the operator. Nonetheless, because of the consistency between the environmental data and the operator's expectations, one event can be taken to be the cause of the other. When this false belief happens, the mental model is erroneously assumed to be valid. We discuss this phenomenon and its potential disastrous consequences using the example of a real commercial air crash. We finally address some implications for systems' design and support tools.
User-interface agent interaction: personalization issues BIBA 129-148
  Silvia Schiaffino; Analia Amandi
Interface agents are computer programs that provide personalized assistance to users with their computer-based tasks. Most interface agents achieve personalization by learning a user's preferences in a given application domain and assisting him according to them. In this work we adopt a different approach to personalization: how to personalize the interaction between interface agents and users in a mixed-initiative interaction context. We have empirically studied a set of interaction issues that agents have to take into account to achieve this goal and we present our results in this article. Some of these personalization issues are: discovering the type of assistant a user wants, learning when (and if) to interrupt the user, discovering how the user wants to be assisted in different contexts. As a result of our experiments, we have defined the components of a user interaction profile that models a user's interaction and assistance preferences. This profile will enable interface agents to enhance and personalize their interaction with users by discovering how to provide each user assistance of the right sort at the right time.

IJHCS 2004 Volume 60 Issue 2

ARTICLE

Models of interactive systems: a case study on programmable user modelling BIBA 149-200
  Ann Blandford; Richard Butterworth; Paul Curzon
Models of interactive systems can be used to answer focused questions about those systems. Making the appropriate choice of modelling technique depends on what questions are being asked. We present two styles of interactive system model and associated verification method. We show how they contrast in terms of tractability, inspectability of assumptions, level of abstraction and reusability of model fragments. These trade-offs are discussed. We discuss how they can be used as part of an integrated formal approach to the analysis of interactive systems where the different formal techniques focus on specific problems raised by empirical investigations. Explanations resulting from the formal analyses can be validated with respect to the empirical data.
   The first modelling style, which we term 'operational', is derived directly from principles of rationality that constrain which user behaviours are modelled. Modelling involves laying out user knowledge of the system and task, and their goals, then applying the principles to reason about the space of rational behaviours. This style supports reasoning about user knowledge and the consequences of particular knowledge in terms of likely behaviours. It is well suited to reasoning about interactions where user knowledge is a key to successful interaction. Such models can readily be implemented as computer programs; one such implementation is presented here.
   Models of the second style, 'abstract', are derived from the operational models and thus retain important aspects of rationality. As a result of the simplification, mathematical proof about selected properties of the interactive system, such as safety properties, can be tractably applied to these models. This style is well suited to cases where the user adopts particular strategies that can be represented succinctly within the model.
   We demonstrate the application of the two styles for understanding a reported phenomenon, using a case study on electronic diaries.
Evolutionary document management and retrieval for specialized domains on the web BIBA 201-241
  Mihye Kim; Paul Compton
Domain-specific information retrieval normally depends on general search engines, which make no use of domain knowledge and require a user to look at a linear display of loosely organized search results or handcrafted specialized systems with a better browsing interface but which are costly to build and maintain. As an alternative, a Web-based document management and retrieval system has been developed aimed at small communities in specialized domains. The system is based on the free annotation of documents by users and is browsed using the concept lattice of formal concept analysis (FCA). A number of knowledge acquisition techniques were developed to aid the annotation process. Experiments were conducted using the system to assist in finding staff and student home pages at the School of Computer Science and Engineering, University of New South Wales. Results indicated that the annotation tools provided a good level of assistance so that documents were easily organized and a lattice-based browsing structure that evolves in an ad hoc fashion provided good efficiency in retrieval performance. Results also indicated that the concept lattice helped take users beyond a narrow search to find other useful documents. These findings suggest that the concept lattice of FCA, supported by annotation techniques is a useful way of supporting the flexible open management of documents required by individuals, small communities and in specialized domains.
Learning concurrency: evolution of students' understanding of synchronization BIBA 243-268
  Yifat Ben-David Kolikant
This paper describes an investigation of high-school students' understanding of synchronization as they studied a course in concurrent and distributed computation. The research followed the students for 2 months, and consisted of both quantitative and qualitative analysis of the students' performance. We found that most of the students had a rich understanding of various synchronization problems. However, many of them developed a pattern-based technique that successfully solved synchronization problems, thus elegantly exempting them from dealing with the dynamics of the synchronization mechanisms; consequently, concepts regarding this theme became inert. Moreover, we were able to uncover reasonable, yet faulty connections that many students had made between the new knowledge and their existing knowledge; these connections were the source of their difficulties. From the findings, we were able to make valuable recommendations for the next version of the course: (a) encouraging alternative connections to existing knowledge by redesigning the instruction, such as representing semaphores in a way that resembles a complex data structure rather than as variables of type integer, and (b) integrating knowledge found to be productive by the students into the instruction to anchor more advanced knowledge, for example utilizing the pattern-based technique as a tool for correctness verification.

IJHCS 2004 Volume 60 Issue 3

ARTICLE

Assessing dimensions of perceived visual aesthetics of web sites BIBA 269-298
  Talia Lavie; Noam Tractinsky
Despite its centrality to human thought and practice, aesthetics has for the most part played a petty role in human-computer interaction research. Increasingly, however, researchers attempt to strike a balance between the traditional concerns of human-computer interaction and considerations of aesthetics. Thus, recent research suggests that the visual aesthetics of computer interfaces is a strong determinant of users' satisfaction and pleasure. However, the lack of appropriate concepts and measures of aesthetics may severely constraint future research in this area. To address this issue, we conducted four studies in order to develop a measurement instrument of perceived web site aesthetics. Using exploratory and confirmatory factor analyses we found that users' perceptions consist of two main dimensions, which we termed "classical aesthetics" and "expressive aesthetics". The classical aesthetics dimension pertains to aesthetic notions that presided from antiquity until the 18th century. These notions emphasize orderly and clear design and are closely related to many of the design rules advocated by usability experts. The expressive aesthetics dimension is manifested by the designers' creativity and originality and by the ability to break design conventions. While both dimensions of perceived aesthetic are drawn from a pool of aesthetic judgments, they are clearly distinguishable from each other. Each of the aesthetic dimensions is measured by a five-item scale. The reliabilities, factor structure and validity tests indicate that these items reflect the two perceived aesthetics dimensions adequately.
Effects of proprioceptive feedback and environmental characteristics on spatial learning in virtual environments BIBA 299-326
  Roy A. Ruddle; Patrick Peruch
The effect of proprioceptive information and environmental characteristics on spatial learning was investigated when participants repeatedly navigated complex three-dimensional virtual mazes. Proprioceptive information, provided by viewing the mazes using a head-mounted display, was found to have little effect. The primary environmental characteristics were layout orthogonality (using paths that intersected at either oblique or 90° angles), lines of sight (controlled using computer-generated "fog"), a visually defined perimeter and global landmarks. Participants travelled less far in orthogonal than oblique environments, even when fog was used to make the distance that participants could see equivalent. The removal of fog caused a further, substantial reduction in the distance participants travelled, indicating the importance of extended lines of sight, as predicted by the architectural theory of space syntax. Global landmarks promoted a similar rate of spatial learning to a visual perimeter.
A grounded theory of the flow experiences of Web users BIBA 327-363
  Steven Pace
This paper presents a grounded theory of the flow experiences of Web users engaged in information-seeking activities. The term flow refers to a state of consciousness that is sometimes experienced by individuals who are deeply involved in an enjoyable activity. The experience is characterized by some common elements: a balance between the challenges of an activity and the skills required to meet those challenges; clear goals and feedback; concentration on the task at hand; a sense of control; a merging of action and awareness; a loss of self-consciousness; a distorted sense of time; and the autotelic experience.
   The grounded theory research method that was employed in this study is a primarily inductive investigative process in which the researcher formulates a theory about a phenomenon by systematically gathering and analysing relevant data. The aim of this research method is building theory, not testing theory. The data that was gathered for this study primarily consisted of semi-structured in-depth interviews with informants of varying gender, age, educational attainments, occupations and Web experience who could recall experiencing flow while using the Web.
Effects of culture on computer-supported international collaborations BIBA 365-380
  Kathleen Swigger; Ferda Alpaslan; Robert Brazile; Michael Monticino
This paper discusses results of a case study from an on-going project to investigate how cultural factors, as identified by the Cultural Perspectives Questionnaire (CPQ), affect the performance of distributed collaborative learning teams. The results indicate that a team's cultural composition is a significant predictor of its performance on programming projects. Cultural attributes most strongly correlated to group performance included those related to attitudes about organizational hierarchy, organizational harmony, trade-offs between future and current needs, and beliefs about how much influence individuals have on their fate. Moreover, the type of programming task affected the strength of the relationship between individual cultural attributes and performance. Participants in the study included computer science students from the University of North Texas (Texas, USA) and students from the Middle East Technical University in Ankara, Turkey. Students were divided into culturally diverse work-teams and assigned programming projects to be completed using special collaborative software. The programming tasks ranged from simple design projects to more complicated programs that required extensive collaboration. Cultural distinctions between work-teams were based upon the students' responses to the CPQ. Project performance was evaluated with respect to programming accuracy, efficiency, completeness, and style. The results presented here have important implications for the formation of distributed collaborations and, in particular, to educational institutions offering distance-learning programs that require team projects.
Evaluating web sites: exploiting user's expectations BIBA 381-416
  Maria De Marsico; Stefano Levialdi
A new goal-based approach to measure usability of web sites is presented, strongly taking into account the customers' expectations, which are often hardly foreseeable as a whole. After a general discussion on web site design issues, we present a short survey of evaluation methods currently used for web sites. We next introduce a new taxonomy of site categories in a three-dimensional space, derived from Aristotle's rhetorical triangle, including different aspects of the site designer's goals. In our approach, we use this taxonomy to identify a number of sites belonging to the same category, in order to carry out a comparative analysis of their features. This analysis is the basis for a two-shot generation of a form for the evaluation of that category of sites. In the first shot, the users fill a generic evaluation form, acquainting them with sites characteristics. They are next asked to perform specific tasks of their choice, according to what they expect from a site of the given category. They note their impressions and list those features they found useful; the analysis of their comments is exploited to formulate statements specific to the given category, to be added to the initial form (second shot). We found that the responses to the second, expanded form, provide more comprehensive criteria for site evaluation, and turn helpful to precisely locate flaws in site functionalities. After testing, our methodology has proved very promising and may be applied for the evaluation of any other site category, most of all those providing a set of special services.

IJHCS 2004 Volume 60 Issue 4

EDITORIAL

Special issue on human-computer interaction research in Japan BIB 417-420
  Kumiyo Nakakoji

ARTICLE

FreeWalk: a social interaction platform for group behaviour in a virtual space BIBA 421-454
  Hideyuki Nakanishi
FreeWalk is a social interaction platform where people and agents can socially and spatially interact with one another. FreeWalk has evolved to support heterogeneous interaction styles including meetings, cross-cultural encounters, and evacuation drills. Each of them is usually supported by an individual virtual environment. This evolution extended the capability to control social interaction. The first prototype only provides people with an environment in which they can gather to talk with one another while the third prototype provides them with a whole situation to behave according to their assigned roles and tasks. FreeWalk1 is a spatial videoconferencing system. In this system, the positions of participants make spontaneous simultaneous conversations possible. Spatial movements are integrated with video-mediated communication. FreeWalk1 is able to make social interaction more casual and relaxed than telephone-like telecommunication media. In contrast to conventional videoconferencing systems, people formed concurrent multiple groups to greet and chat with others. In FreeWalk2, a social agent acts as an in-between of people to reduce the problem of the low social context in virtual spaces. When the agent notes an awkward pause in a conversation, it approaches those involved in the conversation with a suggestion for a new topic to talk about. We used this agent to support cross-cultural communication between Japan and US. Our agent strongly influenced people's impressions of their partners, and also, their stereotypes about their partner's nationality. FreeWalk3 is a virtual city simulator to conduct virtual evacuation drills. This system brings social interaction into crisis management simulation. People can join a virtual scene of a disaster at home. Social agents can also join to play their roles assigned by simulation designers. The system architecture has a split control interface to divide control of multiple agents into high-level instruction for them and simulation of their low-level actions. The interface helps simulation designers to control many agents efficiently.
Social effects of the speed of hummed sounds on human-computer interaction BIBA 455-468
  Noriko Suzuki; Kazuhiko Kakehi; Yugo Takeuchi; Michio Okada
Our research focuses on the nature of voice interaction and activation of psychological tendencies in humans by the power of prosody sounds. This study examines whether people's impressions and behaviours are affected by variations in the speed of hummed sounds. The sounds consist of just prosodic components similar to continuous humming on the open vowel /a/ or /o/ without any language information. In interaction between individuals as well as among animals, temporal structures including voice speed or duration contribute rhythmic interaction and are closely connected to the participants' dynamics of mental or emotional states. We think that this phenomenon can be applied to human-computer interaction, even through the variation in temporal structures of hummed sounds used to reduce the influence of content or meaning in language. Our interactive system mimics the prosodic features of the human voice by using humming-only sounds under three different voice speed conditions: (a) faster, (b) normal, and (c) slower than the original speaker. We examine whether the variation in the sound's speed gives rise to both psychological and behavioural influences in the relationship between the computer and the subject through interaction. Subjects tend to prefer a computer with a normal or faster speaking rate to that with a slower rate on both usefulness and familiarity. Moreover, the speech rate of the subjects changed inversely to the variation in a computer's hummed sounds. This study demonstrates the importance of temporal structure and emphasizes the need for an investigation of the fundamentals at work in interaction.
An interactive visualization method of numerical data based on natural language requirements BIBA 469-488
  Mitsunori Matsushita; Eisaku Maeda; Tsuneaki Kato
This paper proposes an interactive visualization method to support the exploration of data in decision-making and problem solving. Since this method employs an asymmetric communication mode, i.e. taking queries and requests expressed in a natural language as input and answering them with statistical charts, it can convert the normally tedious repetitive human-computer interaction into a felicitous dialogue. This is because the natural language interface allows users to articulate their requests directly and intuitively, and charts and graphics have many benefits when analysing a large amount of data in order to determine overall characteristics or to resolve user questions. The proposed method resolves the conundrum that the appropriateness of a chart depends on the context. In this method, two factors are considered in choosing chart type so as to satisfy the user requirement represented in a natural language: the type of chart displayed and the type of user utterance. Our proposed method allows the data to be visualized interactively to match the changes in the user's viewpoint without interrupting the thinking process.
Meme media architectures for re-editing and redistributing intellectual assets over the Web BIBA 489-526
  Yuzuru Tanaka; Kimihito Ito; Daisuke Kurosaki
While current Web technologies have allowed us to publish intellectual assets in world-wide repositories, and to browse the resulting massive accumulation, we have no effective tools yet to flexibly re-edit and redistribute such intellectual assets for their reuse in different contexts. Open Hypermedia Systems addressed the problem of augmenting third-party applications in 90 s, and more recently Web augmentation. We need extended OHS technologies for the advanced reuse of Web-published intellectual assets through re-editing and redistributing them. Meme media and meme pool technologies will work as such extended Open Hypermedia Systems technologies to annotate, re-edit, and redistribute Web-published assets. This paper reviews the IntelligentPad and IntelligentBox meme media architectures together with their potential applications, and proposes both the use of XML/XSL or XHTML to define two-dimensional meme media objects. When applied to Web contents, meme media technologies make the World Wide Web operate as a meme pool, where people can publish their intellectual assets as Web pages, access some Web pages to extract some of their parts as meme media objects through drag-and-drop operations, visually combine these meme media objects together with other meme media objects to compose new intellectual assets, and publish these assets again as Web pages. Our framework creates a new vista in the circulation and reuse of our knowledge represented as multimedia documents and/or application programs, especially in the field of science.

IJHCS 2004 Volume 60 Issue 5/6

EDITORIAL

HCI Issues in Mobile Computing BIB 527-528
  Parag C. Pendharkar

ARTICLE

A field study of the impact of gender and user's technical experience on the performance of voice-activated medical tracking application BIBA 529-544
  James A. Rodger; Parag C. Pendharkar
Speech recognition is a particularly important technology for mobile computing since it provides a smaller, lighter interface than a keyboard. This paper investigates the impact of user's gender and user's computer experience on the performance of a speech recognition system. Using a field study of 33 users, voice-activated medical tracking application and a mobile healthcare fieldwork environment, we illustrate that the user's gender, user's computer experience and the interaction between the user's gender and computer experience has an impact on the performance of a speech recognition system.
Keystroke-level analysis of Korean text entry methods on mobile phones BIBA 545-563
  Rohae Myung
When predicting text entry performance time on mobile phones, Fitts' law has been used to measure finger movement times on the keypad. However, mental activities, such as remembering numbers and visual searches for the right key on keypads, are necessary for text message exchanges. In order to include physical and mental activities to better materialize phone-operating behaviours, another predictive engineering model, the keystroke-level model (KLM), was used with the concept of GOMS. The traditional KLM has six operators but only two operators, K and M, were used for the evaluation of different text entry interfaces in this study. The time for keystrokes (tK) was calculated with Fitts'-law-based model. To calculate the time for mental activity, phone-operating behaviours were analysed and three mental activities were found: recognizing the intended syllable, recalling the method for composing graphemes and confirming the intended letter. Therefore, the time for accommodating these mental activities is calculated to be 570 ms, which is the sum of time for recognizing and recalling (340 ms) and the time for confirming (230 ms). The KLM-GOMS was developed, validated and utilized to investigate the availability in evaluating different interface alternatives in the design stage and in the comparative study of existing Korean text entry interfaces. The results showed that the model well represented the Korean phone-operating behaviours with the significant statistical test of the average time difference of 6.6%. The results also showed that model was capable of evaluating different text entry interfaces so that it could be used to determine the best Korean text entry interface for the layout standardization of Korean alphabet. In other words, this model could be said to be an efficient tool for the text entry user interface evaluation in the domain of mobile phones without further empirical validations.
A comparison of simple hierarchy and grid metaphors for option layouts on small-size screens BIBA 564-584
  John Christie; Raymond M. Klein; Carolyn Watters
Modern, technologically driven society is characterized by an increase in the rate of mobile device use and an increase in the extent to which these devices are used for more complex tasks than search for phone numbers. While direct consequences of screen-size reduction on task performance are well known, data are lacking on the impact of layout of multiple options in a complex task environment. In this paper we describe the results of an end-user study in which we compared two basic interface designs for the layout of multiple options: a simple hierarchy and a single layer grid. These two designs were presented to users on two screen sizes; a larger size approximating the size of a standard laptop or desktop screen and a smaller size approximating the size of a PDA screen. This study illustrates that while task performance in accessing information was superior using the grid interface rather than the simple hierarchy interface, users preferred the simple hierarchy interface. Even as the complexity of the task increased, the physical size of the screen had a significantly bigger impact on task performance than did the task complexity. These findings indicate that the grid layout should be used when task performance is of the paramount concern and the complexity of choices is not expected to be large. When user preference/satisfaction is more important than task performance the appeal of the simple hierarchy layout may supersede the cost in performance it entails.
Top-down learning strategies: can they facilitate stylus keyboard learning? BIBA 585-598
  Paul Ung-Joon Lee; Shumin Zhai
Learning a new stylus keyboard layout is time-consuming yet potentially rewarding, as optimized virtual keyboards can substantially increase performance for expert users. This paper explores whether the learning curve can be accelerated using top-down learning strategies. In an experiment, one group of participants learned a stylus keyboard layout with top-down methods, such as visuo-spatial grouping of letters and mnemonic techniques, to build familiarity with a stylus keyboard. The other (control) group learned the keyboard by typing sentences. The top-down learning group liked the stylus keyboard better and perceived it to be more effective than the control group. They also had better memory recall performance. Typing performance after the top-down learning process was faster than the initial performance of the control group, but not different from the performance of the control group after they had spent an equivalent amount of time typing. Therefore, top-down learning strategies improved the explicit recall as expected, but the improved memory of the keyboard did not result in quicker typing speeds. These results suggest that quicker acquisition of declarative knowledge does not improve the acquisition speed of procedural knowledge, even during the initial cognitive stage of the virtual keyboard learning. They also suggest that top-down learning strategies can motivate users to learn a new keyboard more than repetitive rehearsal, without any loss in typing performance.
New techniques for usability evaluation of mobile systems BIBA 599-620
  Jesper Kjeldskov; Jan Stage
Usability evaluation of systems for mobile computers and devices is an emerging area of research. This paper presents and evaluates six techniques for evaluating the usability of mobile computer systems in laboratory settings. The purpose of these techniques is to facilitate systematic data collection in a controlled environment and support the identification of usability problems that are experienced in mobile use. The proposed techniques involve various aspects of physical motion combined with either needs for navigation in physical space or division of attention. The six techniques are evaluated through two usability experiments where walking in a pedestrian street was used as a reference. Each of the proposed techniques had some similarities to testing in the pedestrian street, but none of them turned out to be completely comparable to that form of field-evaluation. Seating the test subjects at a table supported identification of significantly more usability problems than any of the other proposed techniques. However a large number of the additional problems identified using this technique were categorized as cosmetic. When increasing the amount of physical activity, the test subjects also experienced a significantly increased subjective workload.
Migratory user interfaces able to adapt to various interaction platforms BIBA 621-639
  Renata Bandelloni; Fabio Paterno
The goal of this work is the design of an environment for supporting runtime migration of Web interfaces among different platforms. This allows users interacting with a Web application to change device and continue their interaction from the same point. The migration takes into account the runtime state of the interactive application and the different features of the devices involved. We consider Web interfaces developed through a multiple-level approach using: the definition of the tasks to support, the abstract description of the user interface and the actual code. The runtime migration engine exploits information regarding the application runtime state and higher-level information on the available target platforms. Runtime application data are used to achieve interaction continuity and preserve usability, while information on the different platforms is considered to adapt the application's appearance and behaviour to the specific device. The paper also discusses a sample application in order to provide concrete examples of the results that can be achieved through our approach.
Pervasive and standalone computing: the perceptual effects of variable multimedia quality BIBA 640-665
  S. R. Gulliver; T. Serif; G. Ghinea
The introduction of multimedia on pervasive and mobile communication devices raises a number of perceptual quality issues; however, limited work has been done examining the three-way interaction between use of equipment, quality of perception and quality of service. Our work measures levels of informational transfer (objective) and user satisfaction (subjective) when users are presented with multimedia video clips at three different frame rates, using four different display devices, simulating variation in participant mobility. Our results will show that variation in frame rate does not impact a user's level of information assimilation, however, does impact a users' perception of multimedia video 'quality'. Additionally, increased visual immersion can be used to increase transfer of video information, but can negatively affect the users' perception of 'quality'. Finally, we illustrate the significant affect of clip-content on the transfer of video, audio and textual information, placing into doubt the use of purely objective quality definitions when considering multimedia presentations.
Supporting serendipitous integration in mobile computing environments BIBA 666-700
  W. Keith Edwards; Mark W. Newman; Jana Z. Sedivy; Trevor F. Smith
In the richly networked world of the near future, mobile computing users will be confronted with an ever-expanding array of devices and services accessible in their environments. In such a world, we cannot expect to have available to us specific applications that allow us to accomplish every conceivable combination of devices that we may wish. Instead, we believe that many of our interactions with the network will be characterized by the use of "general purpose" tools that allow us to discover, use, and integrate multiple devices around us. This paper lays out the case for why we believe that so-called "serendipitous integration" is a necessary fact that we will face in mobile computing, and explores a number of design experiments into supporting end user configuration and control of networked environments through general purpose tools. We present an iterative design approach to creating such tools and their user interfaces, discuss our observations about the challenges of designing for such a world, and then explore a number of tools that take differing design approaches to overcoming these challenges. We conclude with a set of reflections on the user experience issues that we believe are inherent in dealing with ad hoc mobile computing in richly networked environments.
A distributed architecture for searching, retrieving and visualizing complex 3D models on Personal Digital Assistants BIBA 701-716
  A. Sanna; C. Zunino; F. Lamberti
Mobile devices are significantly changing the human-computer interaction. In particular, the ubiquitous access to remote resources is one of the most interesting characteristics achievable by using mobile devices such as Personal Digital Assistants, cellular phones and tablets.
   This paper presents an architecture that allows users to search and visualize complex 3D models over Personal Digital Assistants. A peer-to-peer network of brokers manages queries for searching objects among several data providers. The object selected for visualization is forwarded to a specialized graphics provider; this provider allows the users to investigate the object remotely rendering the scene and sending back to the Personal Digital Assistant the computed image. The user can interactively analyse objects that would not be otherwise visualizable locally on the Personal Digital Assistant.
A cost-effective three-in-one personal digital assistant input control BIBA 717-736
  Andreas Paepcke; Qianying Wang; Sheila Patel; Matthew Wang; Susumu Harada
We attach an inexpensive pressure sensor to the side of a personal digital assistant and use it as three input devices at once. Users can squeeze the device to provide near-continuous input to applications. At the same time the drivers interpret a sudden full squeeze as the push of a virtual button. A user's sudden pressure release while squeezing is detected as the push of a second virtual button. We briefly describe our hardware and signal processing techniques. The remainder of the writing describes an experiment that explores whether users can cope cognitively with the 3-in-1 control. We compare against a three-control setup consisting of a jog wheel and two physical buttons. We show that the three-in-one control enables a 13% faster reaction time over the three-control one, but that the three-in-one control suffers a 4% penalty in the accuracy of users choosing between the two buttons in response to cues from an application. We show that a good choice of application cue is more important for assuring accuracy in the 3-in-1 than in the more traditional set of separate controls.
What makes mobile computer supported cooperative work mobile? Towards a better understanding of cooperative mobile interactions BIBA 737-752
  Gregor Schrott; Johannes Gluckler
Despite the high availability of mobile phones and personal digital assistants with online capabilities, mobile computer supported cooperative work is still in its infancy. So far, only little is known about the distinct attributes of mobile cooperative work in comparison to its stationary counterpart. Across which dimensions does cooperation via mobile devices differ from traditional hard-wired settings and what implications have to be drawn for future research? To bring more light to this question, we conducted an experimental business-case at Frankfurt University with 16 graduate students and analysed their collaborative behaviour across mobile and non-mobile channels of communication over a 5 week period. We find that mobile messages differed from stationary messages in terms of size and that the use of mobile emails prevailed over stationary emails under conditions of stress. Finally, we found that the social structure of mobile communication corresponded with the structure of stationary communication. This indicates that mobile communication technologies support existing communication relations rather than creating new relations. From the perspective of system designers, these results may serve as practical insights into the user behaviour of mobile technologies and might support the future development of mobile computer supported cooperative work environments.
Web navigation structures in cellular phones: the depth/breadth trade-off issue BIBA 753-770
  Avi Parush; Nirit Yuviler-Gavish
One can browse the web with a variety of devices, including hand-held devices such as the cellular phone. The small screen of those devices poses some serious usability issues, one of which is the appropriate hierarchy depth of the web site. In this study, we empirically examined whether a broad navigation structure, which was found to be superior in regular screen-size platforms, also has an advantage for a small-screen device such as the cellular phone where it may require more movements and scrolling between screens of the same hierarchical level. Navigation times and success rates were measured for two search tasks in a mock web site that was built in two versions: one with a broad navigation structure and the other with a deep structure. Both structures were tested with cellular phone emulation and a standard desktop personal computer (PC). Results indicate that performance was better with the broad navigation structure for both the cellular phone and the PC. In addition, performance was better with the PC as compared to the cellular phone, and this difference was pronounced in the broad structure. The results are discussed in terms of the impact of device-independent characteristics of the hierarchy depth along with the theoretical account of increased working memory load, confusion and disorientation associated more with deep structures.
Human-computer interaction issues for mobile computing in a variable work context BIBA 771-797
  Judy York; Parag C. Pendharkar
The current paper takes an introspective look at the human-computer interaction (HCI) issues for mobile computing in a variable work context. We catalogue the current research in four major categories. The major findings of our study are following. (1) A majority of HCI issues, about 58%, fall under the category of computer systems and interface architecture implications. (2) 23% of the articles focus on development and implementation issues. (3) 13% of the articles focus on use and context of computer issues. (4) 6% of the articles focus on human characteristics issues. Further, the literature indicates that the field services is a main application of mobile computing (46%) followed by sales force (21%), health care (17%), fieldwork (8%), insurance claims (4%) and journalism (4%).
Defining and evaluating context for wearable computing BIBA 798-819
  Huw W. Bristow; Chris Baber; James Cross; James F. Knight; Sandra I. Woolley
Defining 'context' has proved to be a non-trivial problem for research in context-awareness. In this paper we address two questions: what features of activity are required to define context? and does the use of context-awareness measurably improve user performance? The first question was addressed by a study of everyday activities, using a Photo Diary method to arrive at a set of Context Identifiers. We feel that it is important to discover what features of activity are needed in order to describe context. Two user trials were carried out to address the second question. We conclude that the use of context improves user task proficiency.