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CHI Tables of Contents: 93X93Y93a93b94-194-2a94-2b94-2c94-2d94-2e95-195-2a95-2b95-2c96-196-2a96-2b96-2c97-197-2a97-2b

Proceedings of ACM CHI'95 Conference on Human Factors in Computing Systems

Fullname:Proceedings of CHI'95 Conference on Human Factors in Computing Systems
Note:Mosaic of Creativity
Location:Denver, Colorado
Dates:1995-May-07 to 1995-May-11
Standard No:ACM ISBN 0-89791-694-8 ACM ISSN 0713-5424; ACM Order Number 608950 Addison-Wesley ISBN 0-201-84705-1; ACM DL: Table of Contents hcibib: CHI95-1
Links:Online Proceedings | Conference Home Page
  1. CHI 1995-05-07 Volume 1
    1. Papers: Cognitive Models
    2. Papers: Programming by Example
    3. Papers: Information Access
    4. Papers: End-User Training and Help
    5. Papers: Multimodal Interfaces
    6. Papers: Studying Work
    7. Papers: Usability Analysis: From Research to Practice
    8. Papers: Learning from Design Experiences
    9. Papers: Using the Information of Others
    10. Papers: Navigating and Scaling in 2D Space
    11. Papers: Advanced Media for Collaboration
    12. Papers: Innovative Interaction I
    13. Papers: Technology at Work
    14. Papers: Visual Display Techniques
    15. Papers: Creating Visualizations
    16. Papers: Making Choices for Communication
    17. Papers: Design Tools
    18. Papers: Information Visualization
    19. Papers: Applying Cognitive Analysis to Design
    20. Papers: Innovative Interaction II
    21. Papers: Pictures and Programming
    22. Papers: Pen Interfaces
    23. Design Briefings: Interfaces for Children
    24. Design Briefings: Redesigning Existing Products
    25. Design Briefings: Managing Complex Data
    26. Design Briefings: Interfaces for Communication
    27. Design Briefings: Designing with Metaphors

CHI 1995-05-07 Volume 1

Papers: Cognitive Models

Display Navigation by an Expert Programmer: A Preliminary Model of Memory BIBAKHTML 3-10
  Erik M. Altmann; Jill H. Larkin; Bonnie E. John
Skilled programmers, working on natural tasks, navigate large information displays with apparent ease. We present a computational cognitive model suggesting how this navigation may be achieved. We trace the model on two related episodes of behavior. In the first, the user acquires information from the display. In the second, she recalls something about the first display and scrolls back to it. The episodes are separated by time and by intervening displays, suggesting that her navigation is mediated by long-term memory, as well as working memory and the display. In the first episode, the model automatically learns to recognize what it sees on the display. In the second episode, a chain of recollections, cued initially by the new display, leads the model to imagine what it might have seen earlier. The knowledge from the first episode recognizes this image, leading the model to scroll in search of the real thing. This model is a step in developing a psychology of skilled programmers working on their own tasks.
Keywords: Psychology of programming, User models, Expert programmers, Display navigation, Program comprehension, Memory, Learning, Soar
Predictive Engineering Models Using the EPIC Architecture for a High-Performance Task BIBAHTML 11-18
  David E. Kieras; Scott D. Wood; David E. Meyer
Engineering models of human performance permit some aspects of usability of interface designs to be predicted from an analysis of the task, and thus can replace to some extent expensive user testing data. Human performance in telephone operator tasks was successfully predicted using engineering models constructed in the EPIC (Executive Process-Interactive Control) architecture for human information-processing, which is especially suited for modeling multimodal, complex tasks. Several models were constructed on an a priori basis to represent different hypotheses about how users coordinate their activities to produce rapid task performance. All of the models predicted the total task time with useful accuracy, and clarified some important properties of the task.
Modeling Time-Constrained Learning in a Highly Interactive Task BIBAKHTML 19-26
  Malcolm I. Bauer; Bonnie E. John
We investigate whether a memory-based learning procedure can explain the development of expertise within the time-constraints of a fast-paced highly interactive task. Our computational cognitive model begins with novice-like knowledge of a domain, and through experience converges on behavior that matches a pre-existing GOMS model of expert human performance. The model coordinates perception, comprehension, strategic planning, learning, memory, and motor action to respond to the time demands of the task while continually improving its performance. Because the model was constructed within the Soar architecture, it is able to make predictions of learning and performance time.
Keywords: Learning, GOMS, Soar, Cognitive models

Papers: Programming by Example

KidSim: End User Programming of Simulations BIBAKHTML 27-34
  Allen Cypher; David Canfield Smith
KidSim is an environment that allows children to create their own simulations. They create their own characters, and they create rules that specify how the characters are to behave and interact. KidSim is programmed by demonstration, so that users do not need to learn a conventional programming language or scripting language. Informal user studies have shown that children are able to create simulations in KidSim with a minimum of instruction, and that KidSim stimulates their imagination.
Keywords: End user programming, Simulations, Programming by demonstration, Graphical rewrite rules, Production systems, Programming by example, User programming
Building Geometry-Based Widgets by Example BIBAKHTML 35-42
  Dan R., Jr. Olsen; Brett Ahlstrom; Douglas Kohlert
Algorithms are presented for creating new widgets by example. The basic model is one of an editable picture which can be mapped to control information. The mappings are learned from examples. The set of possible maps is readily extensible.
Keywords: Widgets, Demonstrational interfaces, Toolkit builder, User interface software
Interactive Sketching for the Early Stages of User Interface Design BIBAKHTML 43-50
  James A. Landay; Brad A. Myers
Current interactive user interface construction tools are often more of a hindrance than a benefit during the early stages of user interface design. These tools take too much time to use and force designers to specify more of the design details than they wish at this early stage. Most interface designers, especially those who have a background in graphic design, prefer to sketch early interface ideas on paper or on a whiteboard. We are developing an interactive tool called SILK that allows designers to quickly sketch an interface using an electronic pad and stylus. SILK preserves the important properties of pencil and paper: a rough drawing can be produced very quickly and the medium is very flexible. However, unlike a paper sketch, this electronic sketch is interactive and can easily be modified. In addition, our system allows designers to examine, annotate, and edit a complete history of the design. When the designer is satisfied with this early prototype, SILK can transform the sketch into a complete, operational interface in a specified look-and-feel. This transformation is guided by the designer. By supporting the early phases of the interface design life cycle, our tool should both ease the development of user interface prototypes and reduce the time needed to create a final interface. This paper describes our prototype and provides design ideas for a production-level system.
Keywords: User interfaces, Design, Sketching, Gesture recognition, Interaction techniques, Programming-by-demonstration, Pen-based computing, Garnet, SILK

Papers: Information Access

Information Foraging in Information Access Environments BIBAKHTML 51-58
  Peter Pirolli; Stuart Card
Information foraging theory is an approach to the analysis of human activities involving information access technologies. The theory derives from optimal foraging theory in biology and anthropology, which analyzes the adaptive value of food-foraging strategies. Information foraging theory analyzes trade-offs in the value of information gained against the costs of performing activity in human-computer interaction tasks. The theory is illustrated by application to information-seeking tasks involving a Scatter/Gather interface, which presents users with a navigable, automatically computed, overview of the contents of a document collection arranged as a cluster hierarchy.
Keywords: Information foraging theory, Information access
TileBars: Visualization of Term Distribution Information in Full Text Information Access BIBAHTML 59-66
  Marti A. Hearst
The field of information retrieval has traditionally focused on textbases consisting of titles and abstracts. As a consequence, many underlying assumptions must be altered for retrieval from full-length text collections. This paper argues for making use of text structure when retrieving from full text documents, and presents a visualization paradigm, called TileBars, that demonstrates the usefulness of explicit term distribution information in Boolean-type queries. TileBars simultaneously and compactly indicate relative document length, query term frequency, and query term distribution. The patterns in a column of TileBars can be quickly scanned and deciphered, aiding users in making judgments about the potential relevance of the retrieved documents.
An Organic User Interface for Searching Citation Links BIBAKHTML 67-73
  Jock D. Mackinlay; Ramana Rao; Stuart K. Card
This paper describes Butterfly, an Information Visualizer application for accessing DIALOG's Science Citation databases across the Internet. Network information often involves slow access that conflicts with the use of highly-interactive information visualization. Butterfly addresses this problem, integrating search, browsing, and access management via four techniques: 1) visualization supports the assimilation of retrieved information and integrates search and browsing activity, 2) automatically-created "link-generating" queries assemble bibliographic records that contain reference information into citation graphs, 3) asynchronous query processes explore the resulting graphs for the user, and 4) process controllers allow the user to manage these processes. We use our positive experience with the Butterfly implementation to propose a general information access approach, called Organic User Interfaces for Information Access, in which a virtual landscape grows under user control as information is accessed automatically.
Keywords: Information visualization, Search, Browsing, Access management, Information retrieval, Organic user interfaces, Data fusion, Hypertext, Citation graphs

Papers: End-User Training and Help

End-User Training: An Empirical Study Comparing On-Line Practice Methods BIBAKHTML 74-81
  Susan Wiedenbeck; Patti L. Zila; Daniel S. McConnell
An empirical study was carried out comparing three kinds of hands-on practice in training users of a software package: exercises, guided-exploration, and a combination of exercises and guided-exploration. Moderate to high experience computer users were trained. Subjects who were trained with exercises or the combined approach did significantly better in both time and errors than those trained using guided-exploration. There were no significant differences between the exercise and the combined approach groups. Thus, it appears that the better performance of these groups can be attributed to the exercise component of their practice.
Keywords: Training, Practice methods, Exercises, Guided-exploration, Minimal manual, End-users, Tutorials
A Comparison of Still, Animated, or Nonillustrated On-Line Help with Written or Spoken Instructions in a Graphical User Interface BIBAKHTML 82-89
  Susan M. Harrison
Current forms of on-line help do not adequately reflect the graphical and dynamic nature of modern graphical user interfaces. Many of today's software applications provide text-based on-line help to assist users in performing a specific task. This report describes a study in which 176 undergraduates received on-line help instructions for completing seven computer-based tasks. Instructions were provided in either written or spoken form with or without still graphic or animated visuals. Results consistently revealed that visuals, either still graphic or animated, in the on-line help instructions enabled the users to significantly perform more tasks in less time and with fewer errors than did users who did not have visuals accompanying the on-line help instructions. Although users receiving spoken instructions were faster and more accurate for the initial set of tasks than were users receiving written instructions, the majority of subjects preferred written instructions over spoken instructions. The results of this study suggest additional empirically-based guidelines to designers for the development of effective on-line help.
Keywords: Graphical user interfaces, On-line help, Visuals, User interface components
Dynamic Generation of Follow Up Question Menus: Facilitating Interactive Natural Language Dialogues BIBAKHTML 90-97
  Vibhu O. Mittal; Johanna D. Moore
Most complex systems provide some form of help facilities. However, typically, such help facilities do not allow users to ask follow up questions or request further elaborations when they are not satisfied with the systems' initial offering. One approach to alleviating this problem is to present the user with a menu of possible follow up questions at every point. Limiting follow up information requests to choices in a menu has many advantages, but there are also a number of issues that must be dealt with in designing such a system. To dynamically generate useful embedded menus, the system must be able to, among other things, determine the context of the request, represent and reason about the explanations presented to the user, and limit the number of choices presented in the menu. This paper discusses such issues in the context of a patient education system that generates a natural language description in which the text is directly manipulable -- clicking on portions of the text causes the system to generate menus that can be used to request elaborations and further information.
Keywords: Hyper-media, Natural language, Intelligent systems, User interface components, Usability engineering

Papers: Multimodal Interfaces

A Generic Platform for Addressing the Multimodal Challenge BIBAKHTML 98-105
  Laurence Nigay; Joelle Coutaz
Multimodal interactive systems support multiple interaction techniques such as the synergistic use of speech and direct manipulation. The flexibility they offer results in an increased complexity that current software tools do not address appropriately. One of the emerging technical problems in multimodal interaction is concerned with the fusion of information produced through distinct interaction techniques. In this article, we present a generic fusion engine that can be embedded in a multi-agent architecture modelling technique. We demonstrate the fruitful symbiosis of our fusion mechanism with PAC-Amodeus, our agent-based conceptual model, and illustrate the applicability of the approach with the implementation of an effective interactive system: MATIS, a Multimodal Airline Travel Information System.
Keywords: Multimodal interactive systems, Software design, Software architecture, I/O devices, Interaction languages, Data fusion
Developing Dual Interfaces for Integrating Blind and Sighted Users: The HOMER UIMS BIBAKHTML 106-113
  Anthony Savidis; Constantine Stephanidis
Existing systems which enable the accessibility of Graphical User Interfaces to blind people follow an "adaptation strategy"; each system adopts its own fixed policy for reproducing visual dialogues to a non-visual form, without knowledge about the application domain or particular dialogue characteristics. It is argued that non-visual User Interfaces should be more than automatically generated adaptations of visual dialogues. Tools are required to facilitate non-visual interface construction, which should allow iterative design and implementation (not supported by adaptation methods). There is a need for "integrated" User Interfaces which are concurrently accessible by both sighted and blind users in order to prevent segregation of blind people in their working environment. The concept of Dual User Interfaces is introduced as the most appropriate basis to address this issue. A User Interface Management System has been developed, called HOMER, which facilitates the development of Dual User Interfaces. HOMER supports the integration of visual and non-visual lexical technologies. In this context, a simple toolkit has been also implemented for building non-visual User Interfaces and has been incorporated in the HOMER system.
Keywords: UIMS, Aids for the impaired, Programming environments
Improving GUI Accessibility for People with Low Vision BIBAKHTML 114-121
  Richard L. Kline; Ephraim P. Glinert
We present UnWindows V1, a set of tools designed to assist low vision users of X Windows in effectively accomplishing two mundane yet critical interaction tasks: selectively magnifying areas of the screen so that the contents can be seen comfortably, and keeping track of the location of the mouse pointer. We describe our software from both the end user's and implementor's points of view, with particular emphasis on issues related to screen magnification techniques. We conclude with details regarding software availability and plans for future extensions.
Keywords: Workstation interfaces, Assistive technology, Low vision, Screen magnification, X window system

Papers: Studying Work

Collaborative Tools and the Practicalities of Professional Work at the International Monetary Fund BIBAKHTML 122-129
  Richard Harper; Abigail Sellen
We show how an ethnographic examination of the International Monetary Fund in Washington, D.C. has implications for the design of tools to support collaborative work. First, it reports how information that requires a high degree of professional judgement in its production is unsuited for most current groupware tools. This is contrasted with the shareability of information which can 'stand-alone'. Second, it reports how effective re-use of documents will necessarily involve paper, or 'paper-like' equivalents. Both issues emphasise the need to take into account social processes in the sharing of certain kinds of information.
Keywords: CSCW, Work practice, Ethnography, Paper documents, Groupware, Professional work, International Monetary Fund
Telephone Operators as Knowledge Workers: Consultants Who Meet Customer Needs BIBAKHTML 130-137
  Michael J. Muller; Rebecca Carr; Catherine Ashworth; Barbara Diekmann; Cathleen Wharton; Cherie Eickstaedt; Joan Clonts
We present two large studies and one case study that make a strong case for considering telephone operators as knowledge workers. We describe a quantitative analysis of the diversity of operators' knowledge work, and of how their knowledge work coordinates with the subtle resources contained within customers' requests. Operators engage in collaborative query refinement with customers, exhibiting a rich set of skilled performances. Earlier reports characterized the operators' role as an intermediary between customer and database. In contrast, we focus on operator's consultative work in which they use computer systems as one type of support for their primarily cognitive activities. Our results suggest that knowledge work may be a subtle feature of many jobs, not only those that are labeled as such. Our methodology may be useful for the analysis of other domains involving skilled workers.
Keywords: Telephone operators, Knowledge work, Expertise, Skilled performance, Participatory design, Participatory analysis
Ethics, Lies and Videotape... BIBAKHTML 138-145
  Wendy E. Mackay
Videotape has become one of the CHI community's most useful technologies: it allows us to analyze users' interactions with computers, prototype new interfaces, and present the results of our research and technical innovations to others. But video is a double-edged sword. It is often misused, however unintentionally. How can we use it well, without compromising our integrity?
   This paper presents actual examples of questionable videotaping practices. Next, it explains why we cannot simply borrow ethical guidelines from other professions. It concludes with a proposal for developing usable ethical guidelines for the capture, analysis and presentation of video.
Keywords: HCI professional issues, Video editing, Ethics, Social computing

Papers: Usability Analysis: From Research to Practice

Multidisciplinary Modeling in HCI Design ...In Theory and in Practice BIBAKHTML 146-153
  Victoria Bellotti; Simon Buckingham Shum; Allan MacLean; Nick Hammond
In one of the largest multidisciplinary projects in basic HCI research to date, multiple analytic HCI techniques were combined and applied within an innovative design context to problems identified by designers of an AV communication system, or media space. The problems were presented to user-, system- and design-analysts distributed across Europe. The results of analyses were integrated and passed back to the designers, and to other domain experts, for assessment. The aim of this paper is to illustrate some theory-based insights gained into key problems in media space design and to convey lessons learned about the process of contributing to design using multiple theoretical perspectives. We also describe some obstacles which must be overcome if such techniques are to be transferred successfully to practice.
Keywords: Theory, Cognitive modelling, Formal methods, Design practice, Argumentation, Design rationale, Media spaces, Multidisciplinary
Design Space Analysis as "Training Wheels" in a Framework for Learning User Interface Design BIBAKHTML 154-161
  J. W. van Aalst; T. T. Carey; D. L. McKerlie
Learning about design is a central component in education for human-computer interaction. We have found Design Space Analysis to be a useful technique for students learning user interface design skills. In the FLUID tool described here, we have combined explicit instruction on design, worked case studies, and problem exercises for learners, yielding an interactive multimedia system to be incorporated into an HCI design course. FLUID is intended as a "training wheels" for learning user interface design. In this paper, we address the question of how this form of teaching might mediate and extend the learning process and we present our observations on Design Space Analysis as a training wheels aid for learning user interface design.
Keywords: HCI education, Design space analysis, Design rationale, Design skills, Interactive multimedia
Practical Education for Improving Software Usability BIBAKHTML 162-169
  John Karat; Tom Dayton
A usable software system is one that supports the effective and efficient completion of tasks in a given work context. In most cases of the design and development of commercial software, usability is not dealt with at the same level as other aspects of software engineering (e.g., clear usability objectives are not set, resources for appropriate activities are not given priority by project management). One common consequence is the assignment of responsibility for usability to people who do not have appropriate training, or who are trained in behavioral sciences rather than in more product-oriented fields such as design or engineering. Relying on our experiences in industrial settings, we make personal suggestions of activities for the realistic and practical alternative of training development team members as usability advocates. Our suggestions help meet the needs specified in the recent Strong et al. [21] report on human-computer interaction education, research, and practice.
Keywords: HCI education, Technology transfer, Participatory design, User-centered design, Usability engineering, Design problem-solving

Papers: Learning from Design Experiences

Evolution of a Reactive Environment BIBAKHTML 170-177
  Jeremy R. Cooperstock; Koichiro Tanikoshi; Garry Beirne; Tracy Narine; William Buxton
A basic tenet of "Ubiquitous computing" (Weiser, 1993 [13]) is that technology should be distributed in the environment (ubiquitous), yet invisible, or transparent. In practice, resolving the seeming paradox arising from the joint demands of ubiquity and transparency is less than simple. This paper documents a case study of attempting to do just that. We describe our experience in developing a working conference room which is equipped to support a broad class of meetings and media. After laying the groundwork and establishing the context in the Introduction, we describe the evolution of the room. Throughout, we attempt to document the rationale and motivation. While derived from a limited domain, we believe that the issues that arise are of general importance, and have strong implications on future research.
Keywords: Case studies, CSCW, Intelligent systems, Reactive environments, Home automation, Design rationale, Office applications
The High-Tech Toolbelt: A Study of Designers in the Workplace BIBAKHTML 178-185
  Tamara Sumner
Many design professionals assemble collections of off-the-shelf software applications into toolbelts to perform their job. These designers use several different tools to create a variety of design representations. This case study shows how designers evolve initially generic toolbelts through a process of domain-enriching to make their own domain-specific design environments. Comparing this practice with theoretical findings concerning design processes highlights the benefits and limitations of this toolbelt approach. A key benefit is its flexible support for creating and evolving multiple design representations. A key limitation is how it hinders iterative design by making it difficult for designers to maintain consistency across the different design representations. This limitation could be remedied if tools could be extended or "tuned" to support the observed domain-enriching process. Such tuning would enable designers to extend tools during use to: (1) support important domain distinctions and (2) define dependencies between different design representations based on these domain distinctions.
Keywords: Design, Design environments, Domain-orientation, End user modifiability, Iterative design, Interoperability, Tailorability, Task-specificity
Time Affordances: The Time Factor in Diagnostic Usability Heuristics BIBAKHTML 186-193
  Alex Paul Conn
A significant body of usability work has addressed the issue of response time in interactive systems. The sharp increase in desktop and networked systems changes the user's focus to a more active diagnostic viewpoint. Today's more experienced networked user is now engaged in complicated activities for which the issue is whether the system is carrying out the appropriate task and how well it is proceeding with tasks that may vary in response time from instantaneous to tens of minutes. We introduce the concept of a time affordance and a set of principles for determining whether the diagnostic information available to the user is rich enough to prevent unproductive and even destructive actions due to an unclear understanding of progress.
Keywords: Usability engineering, Heuristics, Time delay, Affordances, Taxonomy, Principles, Design rationale, Practical guidelines

Papers: Using the Information of Others

Recommending and Evaluating Choices in a Virtual Community of Use BIBAKHTML 194-201
  Will Hill; Larry Stead; Mark Rosenstein; George Furnas
When making a choice in the absence of decisive first-hand knowledge, choosing as other like-minded, similarly-situated people have successfully chosen in the past is a good strategy -- in effect, using other people as filters and guides: filters to strain out potentially bad choices and guides to point out potentially good choices. Current human-computer interfaces largely ignore the power of the social strategy. For most choices within an interface, new users are left to fend for themselves and if necessary, to pursue help outside of the interface. We present a general his tory-of-use method that automates a social method for informing choice and report on how it fares in the context of a fielded test case: the selection of videos from a large set. The positive results show that communal history-of-use data can serve as a powerful resource for use in interfaces.
Keywords: Human-computer interaction, Interaction history, Computer-supported cooperative work, Organizational computing, Browsing, Set-top interfaces, Resource discovery, Video on demand
Pointing the Way: Active Collaborative Filtering BIBAKHTML 202-209
  David Maltz; Kate Ehrlich
Collaborative filtering is based on the premise that people looking for information should be able to make use of what others have already found and evaluated. Current collaborative filtering systems provide tools for readers to filter documents based on aggregated ratings over a changing group of readers. Motivated by the results of a study of information sharing, we describe a different type of collaborative filtering system in which people who find interesting documents actively send "pointers" to those documents to their colleagues. A "pointer" contains a hypertext link to the source document as well as contextual information to help the recipient determine the interest and relevance of the document prior to accessing it. Preliminary data suggest that people are using the system in anticipated and unanticipated ways, as well as creating information "digests".
Keywords: Collaborative filtering, Information retrieval, Hypertext, World Wide Web, Lotus Notes
Social Information Filtering: Algorithms for Automating "Word of Mouth" BIBAKHTML 210-217
  Upendra Shardanand; Patti Maes
This paper describes a technique for making personalized recommendations from any type of database to a user based on similarities between the interest profile of that user and those of other users. In particular, we discuss the implementation of a networked system called Ringo, which makes personalized recommendations for music albums and artists. Ringo's database of users and artists grows dynamically as more people use the system and enter more information. Four different algorithms for making recommendations by using social information filtering were tested and compared. We present quantitative and qualitative results obtained from the use of Ringo by more than 2000 people.
Keywords: Social information filtering, Personalized recommendation systems, User modeling, Information retrieval, Intelligent systems, CSCW

Papers: Navigating and Scaling in 2D Space

A Comparison of User Interfaces for Panning on a Touch-Controlled Display BIBAKHTML 218-225
  Jeff A. Johnson
An experiment was conducted to determine which of several candidate user interfaces for panning is most usable and intuitive: panning by pushing the background, panning by pushing the view/window, and panning by touching the side of the display screen. Twelve subjects participated in the experiment, which consisted of three parts: 1) subjects were asked to suggest panning user interfaces that seemed natural to them, 2) subjects each used three different panning user interfaces to perform a structured panning task, with experimenters recording their performance, and 3) subjects were asked which of the three panning methods they preferred. One panning method, panning by pushing the background, emerged as superior in performance and user preference, and slightly better in intuitiveness than panning by touching the side of the screen. Panning by pushing the view/window fared poorly relative to the others on all measures.
Keywords: Touch display, Touchscreen, Panning, Scrolling, Navigation
Pre-Screen Projection: From Concept to Testing of a New Interaction Technique BIBAKHTML 226-233
  Deborah Hix; James N. Templeman; Robert J. K. Jacob
Pre-screen projection is a new interaction technique that allows a user to pan and zoom integrally through a scene simply by moving his or her head relative to the screen. The underlying concept is based on real-world visual perception, namely, the fact that a person's view changes as the head moves. Pre-screen projection tracks a user's head in three dimensions and alters the display on the screen relative to head position, giving a natural perspective effect in response to a user's head movements. Specifically, projection of a virtual scene is calculated as if the scene were in front of the screen. As a result, the visible scene displayed on the physical screen expands (zooms) dramatically as a user moves nearer. This is analogous to the real world, where the nearer an object is, the more rapidly it visually expands as a person moves toward it. Further, with pre-screen projection a user can navigate (pan and zoom) around a scene integrally, as one unified activity, rather than performing panning and zooming as separate tasks. This paper describes the technique, the real-world metaphor on which it is conceptually based, issues involved in iterative development of the technique, and our approach to its empirical evaluation in a realistic application testbed.
Keywords: Interaction techniques, Empirical studies, Pre-screen projection, Egocentric projection, Formative evaluation, User tasks, Input devices and strategies, Interaction styles, Input/output devices, Polhemus tracker, Visualization, Metaphors, User interface component
Space-Scale Diagrams: Understanding Multiscale Interfaces BIBAKHTML 234-241
  George W. Furnas; Benjamin B. Bederson
Big information worlds cause big problems for interfaces. There is too much to see. They are hard to navigate. An armada of techniques has been proposed to present the many scales of information needed. Space-scale diagrams provide an analytic framework for much of this work. By representing both a spatial world and its different magnifications explicitly, the diagrams allow the direct visualization and analysis of important scale related issues for interfaces.
Keywords: Zoom views, Multiscale interfaces, Fisheye views, Information visualization, GIS, Visualization, User interface components, Formal methods, Design rationale

Papers: Advanced Media for Collaboration

User Embodiment in Collaborative Virtual Environments BIBAKHTML 242-249
  Steve Benford; John Bowers; Lennart E. Fahlen; Chris Greenhalgh; Dave Snowdon
This paper explores the issue of user embodiment within collaborative virtual environments. By user embodiment we mean the provision of users with appropriate body images so as to represent them to others and also to themselves. By collaborative virtual environments we mean multi-user virtual reality systems which explicitly support co-operative work (although we argue that the results of our exploration may also be applied to other kinds of collaborative system). The main part of the paper identifies a list of embodiment design issues including: presence, location, identity, activity, availability, history of activity, viewpoint, actionpoint, gesture, facial expression, voluntary versus involuntary expression, degree of presence, reflecting capabilities, physical properties, active bodies, time and change, manipulating your view of others, representation across multiple media, autonomous and distributed body parts, truthfulness and efficiency. Following this, we show how these issues are reflected in our own DIVE and MASSIVE prototype systems and also show how they can be used to analyse several other existing collaborative systems.
Keywords: Virtual reality, CSCW, Embodiment
Providing Assurances in a Multimedia Interactive Environment BIBAKHTML 250-256
  Doree Duncan Seligmann; Rebecca T. Mercuri; John T. Edmark
In ordinary telephone calls, we rely on cues for the assurance that the connection is active and that the other party is listening to what we are saying. For instance, noise on the line (whether it be someone's voice, traffic sounds, or background static from a bad connection) tells us about the state of our connection. Similarly, the occasional "uhuh" or muffled sounds from a side conversation tells us about the focus and activity of the person on the line. Conventional telephony is based on a single connection for communication between two as such, it has relatively simple assurance needs. Multimedia, multiparty systems increase the complexity of the communication in two orthogonal directions, leading to a concomitant increase in assurance needs. As the complexity of these systems and services grows, it becomes increasingly difficult for users to assess the current state of these services and the level of the user interactions within the systems.
   We have addressed this problem through the use of assurances that are designed to provide information about the connectivity, presence, focus, and activity in an environment that is part virtual and part real. We describe how independent network media services (a virtual meeting room service, a holophonic sound service, an application sharing service, and a 3D augmented reality visualization system) were designed to work together, providing users with coordinated cohesive assurances for virtual contexts in multimedia, multiparty communication and interaction.
Keywords: Auditory I/O, Communication, Virtual reality, Visualization, Graphics, Teleconferencing, Telepresence, User-interfaces
A Virtual Window on Media Space BIBAKHTML 257-264
  William W. Gaver; Gerda Smets; Kees Overbeeke
The Virtual Window system uses head movements in a local office to control camera movement in a remote office. The result is like a window allowing exploration of remote scenes rather than a flat screen showing moving pictures. Our analysis of the system, experience implementing a prototype, and observations of people using it, combine to suggest that it may help overcome the limitations of typical media space configurations. In particular, it seems useful in offering an expanded field of view, reducing visual discontinuities, allowing mutual negotiation of orientation, providing depth information, and supporting camera awareness. The prototype we built is too large, noisy, slow and inaccurate for extended use, but it is valuable in opening a space of possibilities for the design of systems that allow richer access to remote colleagues.
Keywords: CSCW, Groupwork, Media spaces, Video

Papers: Innovative Interaction I

Virtual Reality on a WIM: Interactive Worlds in Miniature BIBAKHTML 265-272
  Richard Stoakley; Matthew J. Conway; Randy Pausch
This paper explores a user interface technique which augments an immersive head tracked display with a hand-held miniature copy of the virtual environment. We call this interface technique the Worlds in Miniature (WIM) metaphor. In addition to the first-person perspective offered by a virtual reality system, a World in Miniature offers a second dynamic viewport onto the virtual environment. Objects may be directly manipulated either through the immersive viewport or through the three-dimensional viewport offered by the WIM.
   In addition to describing object manipulation, this paper explores ways in which Worlds in Miniature can act as a single unifying metaphor for such application independent interaction techniques as object selection, navigation, path planning, and visualization. The WIM metaphor offers multiple points of view and multiple scales at which the user can operate, without requiring explicit modes or commands.
   Informal user observation indicates that users adapt to the Worlds in Miniature metaphor quickly and that physical props are helpful in manipulating the WIM and other objects in the environment.
Keywords: Virtual reality, Three-dimensional interaction, Two-handed interaction, Information visualization
The "Prince" Technique: Fitts' Law and Selection Using Area Cursors BIBAK 273-279
  Paul Kabbash; William Buxton
In most GUIs, selection is effected by placing the point of the mouse-driven cursor over the area of the object to be selected. Fitts' law is commonly used to model such target acquisition, with the term A representing the amplitude, or distance, of the target from the cursor, and W the width of the target area. As the W term gets smaller, the index of difficulty of the task increases. The extreme case of this is when the target is a point. In this paper, we show that selection in such cases can be facilitated if the cursor is an area, rather than a point. Furthermore, we show that when the target is a point and the width of the cursor is W, that Fitts' law still holds. An experiment is presented and the implications of the technique are discussed for both 2D and 3D interfaces.
Keywords: Input techniques, Graphical user interfaces, Fitts' law, Haptic input
Applying Electric Field Sensing to Human-Computer Interfaces BIBAKHTML 280-287
  Thomas G. Zimmerman; Joshua R. Smith; Joseph A. Paradiso; David Allport; Neil Gershenfeld
A non-contact sensor based on the interaction of a person with electric fields for human-computer interface is investigated. Two sensing modes are explored: an external electric field shunted to ground through a human body, and an external electric field transmitted through a human body to stationary receivers. The sensors are low power (milliwatts), high resolution (millimeter) low cost (a few dollars per channel), have low latency (millisecond), high update rate (1 kHz), high immunity to noise (>72 dB), are not affected by clothing, surface texture or reflectivity, and can operate on length scales from microns to meters. Systems incorporating the sensors include a finger mouse, a room that knows the location of its occupant, and people-sensing furniture. Haptic feedback using passive materials is described. Also discussed are empirical and analytical approaches to transform sensor measurements into position information.
Keywords: User interface, Input device, Gesture interface, Non-contact sensing, Electric field

Papers: Technology at Work

Learning to Write Together Using Groupware BIBAKHTML 288-295
  Alex Mitchell; Ilona Posner; Ronald Baecker
Most studies of collaborative writing have focused on mature writers who have extensive experience with the process of writing together. Typically, these studies also deal with short, somewhat artificial tasks carried out in a laboratory, and thus do not extend over a period of time as real writing usually does.
   This paper describes an ethnographic study of collaborative writing by two groups of 4 grade six students using synchronous collaborative writing software for one hour per week over a 12 week period. Despite initially having little appreciation of what it means to write together, and no experience in synchronous collaborative writing, both groups produced nearly one dozen short collaboratively conceived, written, and edited documents by the end of the study.
   A careful analysis of video tape records, written documents, questionnaires, and interviews demonstrated the importance of concepts such as awareness, ownership, and control in the writing process, and highlighted many examples of strengths and weaknesses in the writing software.
Keywords: CSCW, Groupware, Group work, Collaborative writing, Learning to write, Novice writers, Ethnography
Electronic Futures Markets versus Floor Trading: Implications for Interface Design BIBAKHTML 296-303
  Satu S. Parikh; Gerald L. Lohse
The primary concern in designing an interface for an electronic trading system is the impact on market liquidity [9]. Current systems make use of efficient order-execution algorithms but fail to capture elements of the trading floor that contribute to an efficient market [9]. We briefly describe tasks conducted in futures pit trading and current off-hours electronic trading systems. Understanding the tasks helps define key components to an interface for electronic trading. These include visualization of the market and its participants, a trading process which allows active participation and price discovery as well as concurrent interaction among each of the participants.
Keywords: Futures trading, Automated exchange, Trading pits, Interface design, Electronic markets
Dinosaur Input Device BIBAKHTML 304-309
  Brian Knep; Craig Hayes; Rick Sayre; Tom Williams
We present a system for animating an articulate figure using a physical skeleton, or armature, connected to a workstation. The skeleton is covered with sensors that monitor the orientations of the joints and send this information to the computer via custom-built hardware. The system is precise, fast, compact, and easy to use. It lets traditional stop-motion animators produce animation on a computer without requiring them to learn complex software. The working environment is very similar to the traditional environment but without the nuisances of lights, a camera, and delicate foam-latex skin. The resulting animation lacks the artifacts of stop-motion animation, the pops and jerkiness, and yet retains the intentional subtleties and hard stops that computer animation often lacks.
Keywords: Entertainment applications, Motion capture, Animation

Papers: Visual Display Techniques

Dynamic Stereo Displays BIBAKHTML 310-316
  Colin Ware
Based on a review of the facts about human stereo vision, a case is made that the stereo processing mechanism is highly flexible. Stereopsis seems to provide only local additional depth information, rather than defining the overall 3D geometry of a perceived scene. New phenomenological and experimental evidence is presented to support this view. The first demonstration shows that kinetic depth information dominates stereopsis in a depth cue conflict. Experiment 1 shows that dynamic changes in effective eye separation are not noticed if they occur over a period of a few seconds. Experiment 2 shows that subjects who are given control over their effective eye separation, can comfortably work with larger than normal eye separations when viewing a low relief scene. Finally, an algorithm is presented for the generation of dynamic stereo images designed to reduce the normal eye strain that occurs due to the mis-coupling of focus and vergence cues.
Keywords: Stereo displays, Virtual reality, 3D displays
Transparent Layered User Interfaces: An Evaluation of a Display Design to Enhance Focused and Divided Attention BIBAKHTML 317-324
  Beverly L. Harrison; Hiroshi Ishii; Kim J. Vicente; William A. S. Buxton
This paper describes a new research program investigating graphical user interfaces from an attentional perspective (as opposed to a more traditional visual perception approach). The central research issue is how we can better support both focusing attention on a single interface object (without distraction from other objects) and dividing or time sharing attention between multiple objects (to preserve context or global awareness). This attentional trade-off seems to be a central but as yet comparatively ignored issue in many interface designs. To this end, this paper proposes a framework for classifying and evaluating user interfaces with semi-transparent windows, menus, dialogue boxes, screens, or other objects. Semi-transparency fits into a more general proposed display design space of "layered" interface objects. We outline the design space, task space, and attentional issues which motivated our research. Our investigation is comprised of both empirical evaluation and more realistic application usage. This paper reports on the empirical results and summarizes some of the application findings.
Keywords: Display design, Evaluation, Transparency, User interface design, Interaction technology
User-Centered Video: Transmitting Video Images Based on the User's Interest BIBAKHTML 325-330
  Kimaya Yamaashi; Yukihiro Kawamata; Masayuki Tani; Hidekazu Matsumoto
Many applications, such as video conference systems and remotely controlled systems, need to transmit multiple video images through narrow band networks. However, high quality transmission of the video images is not possible within the network bandwidth.
   This paper describes a technique, User-Centered Video (UCV), which transmits multiple video images through a network by changing quality of the video images based on a user's interest. The UCV assigns a network data rate to each video image in proportion to the user's interest. The UCV transmits video images of interest with high quality, while degrading the remaining video images. The video images are degraded in the space and time domains (e.g., spatial resolution, frame rate) to fit them into the assigned data rates. The UCV evaluates the degree of the user's interest based on the window layouts. The user thereby obtains both the video images of interest, in detail, and the global context of video images, even through a narrow band network.
Keywords: Networks or communication, Digital video, Compression, User's interest, Computing resources

Papers: Creating Visualizations

Visualizing Complex Hypermedia Networks through Multiple Hierarchical Views BIBAKHTML 331-337
  Sougata Mukherjea; James D. Foley; Scott Hudson
Our work concerns visualizing the information space of hypermedia systems using multiple hierarchical views. Although overview diagrams are useful for helping the user to navigate in a hypermedia system, for any real-world system they become too complicated and large to be really useful. This is because these diagrams represent complex network structures which are very difficult to visualize and comprehend. On the other hand, effective visualizations of hierarchies have been developed. Our strategy is to provide the user with different hierarchies, each giving a different perspective to the underlying information space to help the user better comprehend the information. We propose an algorithm based on content and structural analysis to form hierarchies from hypermedia networks. The algorithm is automatic but can be guided by the user. The multiple hierarchies can be visualized in various ways. We give examples of the implementation of the algorithm on two hypermedia systems.
Keywords: Hypermedia, Overview diagrams, Information visualization, Hierarchization
SageBook: Searching Data-Graphics by Content BIBAKHTML 338-345
  Mei C. Chuah; Steven F. Roth; John Kolojejchick; Joe Mattis; Octavio Juarez
Currently, there are many hypertext-like tools and database retrieval systems that use keyword search as a means of navigation. While useful for certain tasks, keyword search is insufficient for browsing databases of data-graphics. SageBook is a system that searches among existing data-graphics, so that they can be reused with new data. In order to fulfill the needs of retrieval and reuse, it provides: 1) a direct manipulation, graphical query interface; 2) a content description language that can express important relationships for retrieving data-graphics; 3) automatic description of stored data-graphics based on their content; 4) search techniques sensitive to the structure and similarity among data-graphics; 5) manual and automatic adaptation tools for altering data-graphics so that they can be reused with new data.
Keywords: Data-visualization, Data-graphic design, Automatic presentation, Intelligent interfaces, Content-based search, Image-retrieval, Information-retrieval
Finding and Using Implicit Structure in Human-Organized Spatial Layouts of Information BIBAKHTML 346-353
  Frank M., III Shipman; Catherine C. Marshall; Thomas P. Moran
Many interfaces allow users to manipulate graphical objects, icons representing underlying data or the data themselves, against a spatial backdrop or canvas. Users take advantage of the flexibility offered by spatial manipulation to create evolving lightweight structures. We have been investigating these implicit organizations so we can support user activities like information management or exploratory analysis. To accomplish this goal, we have analyzed the spatial structures people create in diverse settings and tasks, developed algorithms to detect the common structures we identified in our survey, and experimented with new facilities based on recognized structure. Similar recognition-based functionality can be used within many common applications, providing more support for users' activities with less attendant overhead.
Keywords: Emergent structure, Spatial diagrams, Spatial structure recognition, Informal systems, Hypermedia

Papers: Making Choices for Communication

Comparison of Face-To-Face and Distributed Presentations BIBAKHTML 354-361
  Ellen A. Isaacs; Trevor Morris; Thomas K. Rodriguez; John C. Tang
As organizations become distributed across multiple sites, they are looking to technology to help support enterprise-wide communication and training to distant locations. We developed an application called Forum that broadcasts live video, audio, and slides from a speaker to distributed audiences at their computer desktops. We studied how distributed presentations over Forum differed from talks given in face-to-face settings. We found that Forum attracted larger audiences, but the quality of interaction was perceived to be lower. Forum appeared to provide more flexible and effective use of slides and other visual materials. On the whole, audiences preferred to watch talks over Forum but speakers preferred to give talks in a local setting. The study raises issues about how to design this technology and how to help people discover effective ways of using it.
Keywords: Distributed presentations, Distance learning, Computer-supported cooperative work (CSCW), Video conferencing, Multimedia, Organizational communication
What Mix of Video and Audio is Useful for Small Groups Doing Remote Real-Time Design Work? BIBAKHTML 362-368
  Judith S. Olson; Gary M. Olson; David K. Meader
This study reports the second in a series of related studies of the ways in which small groups work together, and the effects of various kinds of technology support. In this study groups of three people worked for an hour and a half designing an Automated Post Office. Our previous work showed that people doing this task produced higher quality designs when they were able to use a shared-editor to support their emerging design. This study compares the same kinds of groups now working at a distance, connected to each other both by this shared editor and either with high-quality stereo audio or the same audio plus high-quality video. The video was arranged so that people made eye contact and spatial relations were preserved, allowing people to have a sense of who was doing what in a way similar to that in face-to-face work. Results showed that with video, work was as good in quality as that face-to face; with audio only, the quality of the work suffered a small but significant amount. When working at a distance, however, groups spent more time clarifying to each other and talking longer about how to manage their work. Furthermore, groups rated the audio-only condition as having a lower discussion quality, and reported more difficulty communicating Perceptions suffer without video, and work is accomplished in slightly different manner, but the quality of work suffers very little.
Keywords: Group support system, Remote work, Concurrent editing, Small group behavior, Desktop video
Designing SpeechActs: Issues in Speech User Interfaces BIBAKHTML 369-376
  Nicole Yankelovich; Gina-Anne Levow; Matt Marx
SpeechActs is an experimental conversational speech system. Experience with redesigning the system based on user feedback indicates the importance of adhering to conversational conventions when designing speech interfaces, particularly in the face of speech recognition errors. Study results also suggest that speech-only interfaces should be designed from scratch rather than directly translated from their graphical counterparts. This paper examines a set of challenging issues facing speech interface designers and describes approaches to address some of these challenges.
Keywords: Speech interface design, Speech recognition, Auditory I/O, Discourse, Conversational interaction

Papers: Design Tools

Integrating Task and Software Development for Object-Oriented Applications BIBAKHTML 377-384
  Mary Beth Rosson; John M. Carroll
We describe an approach to developing object-oriented applications that seeks to integrate the design of user tasks with the design of software implementing these tasks. Using the Scenario Browser -- an experimental environment for developing Smalltalk applications -- a designer employs a single set of task scenarios to envision and reason about user needs and concerns and to experiment with and refine object-oriented software abstractions. We argue that the shared context provided by the scenarios promotes rapid feedback between usage and software concerns, so that mutual constraints and opportunities can be recognized and addressed early and continuingly in the development process.
Keywords: Prototyping, Design tools, Scenarios, Object-oriented programming, Software engineering, Design rationale
Using Computational Critics to Facilitate Long-Term Collaboration in User Interface Design BIBAKHTML 385-392
  Uwe Malinowski; Kumiyo Nakakoji
User interface design and end-user adaptation during the use of the system should be viewed as an ongoing collaborative design process among interface designers and end-users. Existing approaches have focused on the two activities separately and paid little attention to integration of the two by supporting their asynchronous collaboration over a long period of time throughout the evolution of the interface design. Our knowledge-based domain-oriented user interface design environments serve both as design media and as communication media among interface designers and end-users. An embedded computational critiquing mechanism not only identifies possible problematic situations in a design for user interface designers and end-users but also facilitates asynchronous communication among stakeholders. The presentation of critiquing messages often triggers designers and end-users to articulate design rationale by describing how they responded to the critiques. The recorded design rationale mediates collaboration among end-users and user interface designers during the end-user adaptation and redesign of the interface by providing background context for a design decision.
Keywords: Usability engineering, Collaborative design, Design rationale, User interface design environments, Critiquing systems, End-user adaptation, Process control
A Theoretically Motivated Tool for Automatically Generating Command Aliases BIBAKHTML 393-400
  Sarah Nichols; Frank E. Ritter
A useful approach towards improving interface design is to incorporate known HCI theory in design tools. As a step toward this, we have created a tool incorporating several known psychological results (e.g., alias generation rules and the keystroke model). The tool, simple additions to a spreadsheet developed for psychology, helps create theoretically motivated aliases for command line interfaces, and could be further extended to other interface types. It was used to semi-automatically generate a set of aliases for the interface to a cognitive modelling system. These aliases reduce typing time by approximately 50%. Command frequency data, necessary for computing time savings and useful for arbitrating alias clashes, can be difficult to obtain. We found that expert users can quickly provide useful and reasonably consistent estimates, and that the time savings predictions were robust across their predictions and when compared with a uniform command frequency distribution.
Keywords: HCI design tools, Keystroke-Level Model, Design problem solving

Papers: Information Visualization

A Focus+Context Technique Based on Hyperbolic Geometry for Visualizing Large Hierarchies BIBAKHTML 401-408
  John Lamping; Ramana Rao; Peter Pirolli
We present a new focus+context (fisheye) technique for visualizing and manipulating large hierarchies. Our technique assigns more display space to a portion of the hierarchy while still embedding it in the context of the entire hierarchy. The essence of this scheme is to lay out the hierarchy in a uniform way on a hyperbolic plane and map this plane onto a circular display region. This supports a smooth blending between focus and context, as well as continuous redirection of the focus. We have developed effective procedures for manipulating the focus using pointer clicks as well as interactive dragging, and for smoothly animating transitions across such manipulation. A laboratory experiment comparing the hyperbolic browser with a conventional hierarchy browser was conducted.
Keywords: Hierarchy display, Information visualization, Fisheye display, Focus+Context technique
GeoSpace: An Interactive Visualization System for Exploring Complex Information Spaces BIBAKHTML 409-414
  Ishantha Lokuge; Suguru Ishizaki
This paper presents a reactive interface display which allows information seekers to explore complex information spaces. We have adopted information seeking dialogue as a fundamental model of interaction and implemented a prototype system in the mapping domain -- GeoSpace -- which progressively provides information upon a user's input queries. Domain knowledge is represented in a form of information presentation plan modules, and an activation spreading network technique is used to determine the relevance of information. The reactive nature of the activation spreading network, combined with visual design techniques, such as typography, color and transparency enables the system to support the information seeker in exploring the complex information space. The system also incorporates a simple learning mechanism which enables the system to adapt the display to a particular user's preferences. GeoSpace allows users to rapidly identify information in a dense display and it can guide a users' attention in a fluid manner while preserving overall context.
Keywords: Interactive techniques, Intelligent interfaces, Cartography, Multi-layer, Graphics presentation, Activation spreading network
Enhanced Dynamic Queries via Movable Filters BIBAKHTML 415-420
  Ken Fishkin; Maureen C. Stone
Traditional database query systems allow users to construct complicated database queries from specialized database language primitives. While powerful and expressive, such systems are not easy to use, especially for browsing or exploring the data. Information visualization systems address this problem by providing graphical presentations of the data and direct manipulation tools for exploring the data. Recent work has reported the value of dynamic queries coupled with two-dimensional data representations for progressive refinement of user queries. However, the queries generated by these systems are limited to conjunctions of global ranges of parameter values. In this paper, we extend dynamic queries by encoding each operand of the query as a Magic Lens filter. Compound queries can be constructed by overlapping the lenses. Each lens includes a slider and a set of buttons to control the value of the filter function and to define the composition operation generated by overlapping the lenses. We demonstrate a system that supports multiple, simultaneous, general, real-valued queries on databases with incomplete data, while maintaining the simple visual interface of dynamic query systems.
Keywords: Viewing filter, Lens, Database query, Dynamic queries, Magic lens, Visualization

Papers: Applying Cognitive Analysis to Design

Turning Research into Practice: Characteristics of Display-Based Interaction BIBAKHTML 421-428
  Marita Franzke
This research investigates how several characteristics of display-based systems support or hinder the exploration and retention of the functions needed to perform tasks in a new application. In particular it is shown how the combination of the type of interface action, the number of interaction objects presented on the screen, and the quality of the label associated with these objects interact in supporting discovery and retention of the functionality embedded in those systems. An experiment is reported which provides empirical evidence for Polson & Lewis's CE+ theory of exploratory learning of computer systems [11]. It also extends this theory and therefore leads to a refinement of the cognitive walkthrough procedure that was derived from it. The study uses an experimental method that combines observations from realistically complex task scenarios with a detailed analysis of the observed performance.
Keywords: Exploration, Retention, Display-based systems, Direct manipulation, Cognitive theory, Cognitive walkthrough, Experimental method
Learning and Using the Cognitive Walkthrough Method: A Case Study Approach BIBAKHTML 429-436
  Bonnie E. John; Hilary Packer
We present a detailed case study, drawn from many information sources, of a computer scientist learning and using Cognitive Walkthroughs to assess a multi-media authoring tool. This study results in several clear messages to both system designers and to developers of evaluation techniques: this technique is currently learnable and usable, but there are several areas where further method-development would greatly contribute to a designer's use of the technique. In addition, the emergent picture of the process this evaluator went through to produce his analysis sets realistic expectations for other novice evaluators who contemplate learning and using Cognitive Walkthroughs.
Keywords: Usability engineering, Inspection methods, Cognitive Walkthrough
What Help Do Users Need?: Taxonomies for On-Line Information Needs and Access Methods BIBAKHTML 437-441
  A. W. Roesler; S. G. McLellan
The feasibility of using a general on-line help taxonomy scheme as the starting point for our interactive graphical applications' on-line help specifications was investigated. We assumed that using such a taxonomy would make it easier for users of the help system, regardless of the application used. The literature, software conferences, trade shows, and the like point to enormous differences of opinion about what help even IS, much less how it should be designed, accessed, displayed, stored, or maintained. While much research described sound design principles and access methods, very little was available on WHAT to organize or access. Our effort on defining a taxonomy for on-line help was based upon three tests:
  • Test1, a Wizard-of-Oz usability study of an application that identified what
       types of on-line help our interactive software users actually ask for;
  • Test2, a test that validated a general taxonomy for on-line help content for
       help providers, based on the results of Test1, and a general taxonomy of
       access methods derived from these content types; and
  • Test3, a repeat of Test1, substituting a prototype help system for
       Wizard-of-Oz help that successfully validated the usability of both on-line
       help content and access taxonomies for help users. This paper summarizes the results of all three tests, highlighting the proposed taxonomies and key findings about them from Test2. Together, the results from all tests indicate that a general taxonomy of information needs and the taxonomy of access methods to particular information types make it easy both for help providers to understand what information they need to supply and for help users to find the help they need quickly.
    Keywords: On-line help, Taxonomy, User interface, Usability, Empirical evaluation, Methodology
  • Papers: Innovative Interaction II

    Bricks: Laying the Foundations for Graspable User Interfaces BIBAKHTML 442-449
      George W. Fitzmaurice; Hiroshi Ishii; William Buxton
    We introduce the concept of Graspable User Interfaces that allow direct control of electronic or virtual objects through physical handles for control. These physical artifacts, which we call "bricks," are essentially new input devices that can be tightly coupled or "attached" to virtual objects for manipulation or for expressing action (e.g., to set parameters or for initiating processes). Our bricks operate on top of a large horizontal display surface known as the "ActiveDesk." We present four stages in the development of Graspable UIs: (1) a series of exploratory studies on hand gestures and grasping; (2) interaction simulations using mock-ups and rapid prototyping tools; (3) a working prototype and sample application called GraspDraw; and (4) the initial integrating of the Graspable UI concepts into a commercial application. Finally, we conclude by presenting a design space for Bricks which lay the foundation for further exploring and developing Graspable User Interfaces.
    Keywords: Input devices, Graphical user interfaces, Graspable user interfaces, Haptic input, Two-handed interaction, Prototyping, Computer augmented environments, Ubiquitous computing
    Situated Facial Displays: Towards Social Interaction BIBAKHTML 450-455
      Akikazu Takeuchi; Taketo Naito
    Most interactive programs have been assuming interaction with a single user. We propose the notion of "Social Interaction" as a new interaction paradigm between multiple humans and computers. Social interaction requires that first a computer has the multiple participants model, second its behaviors are not only determined by internal logic but also affected by perceived external situations, and finally it actively joins the interaction. An experimental system with these features was developed. It consists of three subsystems, a vision subsystem that processes motion video input to examine an external situation, an action/reaction subsystem that generates an action based on internal logic of a task and a situated reaction triggered by perceived external situation, and a facial animation subsystem that generates a three-dimensional face capable of various facial displays. From the experiment using the system with a number of subjects, we found that subjects generally tended to try to interpret facial displays of the computer. Such involvement prevented them from concentrating on a task. We also found that subjects never recognized situated reactions of the computer that were unrelated to the task although they unconsciously responded to them. These findings seem to imply subliminal involvement of the subjects caused by facial displays and situated reactions.
    Keywords: User interface design, Multimodal interfaces, Facial expression, Anthropomorphism, Subliminal involvement
    GloveTalkII: An Adaptive Gesture-to-Formant Interface BIBAKHTML 456-463
      Sidney Fels; Geoffrey Hinton
    Glove-TalkII is a system which translates hand gestures to speech through an adaptive interface. Hand gestures are mapped continuously to 10 control parameters of a parallel formant speech synthesizer. The mapping allows the hand to act as an artificial vocal tract that produces speech in real time. This gives an unlimited vocabulary, multiple languages in addition to direct control of fundamental frequency and volume. Currently, the best version of Glove-TalkII uses several input devices (including a Cyberglove, a ContactGlove, a polhemus sensor, and a foot-pedal), a parallel formant speech synthesizer and 3 neural networks. The gesture-to-speech task is divided into vowel and consonant production by using a gating network to weight the outputs of a vowel and a consonant neural network. The gating network and the consonant network are trained with examples from the user. The vowel network implements a fixed, user-defined relationship between hand-position and vowel sound and does not require any training examples from the user. Volume, fundamental frequency and stop consonants are produced with a fixed mapping from the input devices. One subject has trained for about 100 hours to speak intelligibly with Glove-TalkII. He passed through eight distinct stages while learning to speak. He speaks slowly with speech quality similar to a text-to-speech synthesizer but with far more natural-sounding pitch variations.
    Keywords: Gesture-to-speech device, Gestural input, Speech output, Speech acquisition, Adaptive interface, Talking machine

    Papers: Pictures and Programming

    Pictures as Input Data BIBAKHTML 464-471
      Douglas C. Kohlert; Dan R., Jr. Olsen
    This paper suggests that there exists a large class of inherently graphical applications that could use pictures as their primary input data. These applications have no need to store input data in any other format and thus eliminate the need to do conversions between input data and a graphical representation. Since the graphical representation is the only representation of the data, such applications allow users to edit an application's input data by manipulating pictures in a drawing editor. Such an environment would be ideal for users of pen-based machines since data would not have to be entered via a keyboard, instead a gesture based drawing editor could be used. CUPID, which is a tool for Creating User-Interfaces that use Pictures as Input Data, is presented.
    Keywords: Visual languages, Picture parsing, Picture-based applications
    Planning-Based Control of Interface Animation BIBAKHTML 472-479
      David Kurlander; Daniel T. Ling
    Animations express a sense of process and continuity that is difficult to convey through other techniques. Although interfaces can often benefit from animation, User Interface Management Systems (UIMSs) rarely provide the tools necessary to easily support complex, state-dependent application output, such as animations. Here we describe Player, an interface component that facilitates sequencing these animations. One difficulty of integrating animations into interactive systems is that animation scripts typically only work in very specific contexts. Care must be taken to establish the required context prior to executing an animation. Player employs a precondition and postcondition-based specification language, and automatically computes which animation scripts should be invoked to establish the necessary state. Player's specification language has been designed to make it easy to express the desired behavior of animation controllers. Since planning can be a time-consuming process inappropriate for interactive systems, Player precompiles the plan-based specification into a state machine that executes far more quickly. Serving as an animation controller, Player hides animation script dependencies from the application. Player has been incorporated into the Persona UIMS, and is currently used in the Peedy application.
    Keywords: Animation, Planning, User interface management systems, UIMS, User interface components, 3D interfaces
    Bridging the Gulf Between Code and Behavior in Programming BIBAKHTML 480-486
      Henry Lieberman; Christopher Fry
    Program debugging can be an expensive, complex and frustrating process. Conventional programming environments provide little explicit support for the cognitive tasks of diagnosis and visualization faced by the programmer. ZStep 94 is a program debugging environment designed to help the programmer understand the correspondence between static program code and dynamic program execution. Some of ZStep 94's innovations include:
  • An animated view of program execution, using the very same display used to
       edit the source code
  • A window that displays values which follows the stepper's focus
  • An incrementally-generated complete history of program execution and output
  • "Video recorder" controls to run the program in forward and reverse
       directions and control the level of detail displayed
  • One-click access from graphical objects to the code that drew them
  • One-click access from expressions in the code to their values and graphical
    Keywords: Programming environments, Psychology of programming, Debugging, Educational applications, Software visualization
  • Papers: Pen Interfaces

    Implicit Structures for Pen-Based Systems within a Freeform Interaction Paradigm BIBAKHTML 487-494
      Thomas P. Moran; Patrick Chiu; William van Melle; Gordon Kurtenbach
    This paper presents a scheme for extending an informal, pen-based whiteboard system (Tivoli on the Xerox LiveBoard) to provide a structured editing capability without violating its free expression and ease of use. The scheme supports list, text, table, and outline structures over handwritten scribbles and typed text. The scheme is based on the system temporarily perceiving the "implicit structure" that humans see in the material, which is called a WYPIWYG (What You Perceive Is What You Get) capability. The design techniques, principles, trade-offs, and limitations of the scheme are discussed. A notion of "freeform interaction" is proposed to position the system with respect to current user interface techniques.
    Keywords: Freeform interaction, Implicit structure, Pen-based systems, Scribbling, Whiteboard metaphor, Informal systems, Recognition-based systems, Perceptual support, List structures, Gestural interfaces, User interface design
    Back to the Future: Pen and Paper Technology Supports Complex Group Coordination BIBAKHTML 495-502
      Steve Whittaker; Heinrich Schwarz
    Despite a wealth of electronic group tools for co-ordinating the software development process, instead we find many groups choosing apparently outmoded "material" tools in critical projects. To understand the limitations of current electronic tools, we studied two groups, contrasting the effectiveness of both kinds of tools. We show that the size, public location and physical qualities of material tools engender certain crucial group processes that current on-line technologies fail to support. A large wallboard located in a public area promoted group interaction around the board, it enabled collaborative problem solving, as well as informing individuals about the local and global progress of the project. Furthermore, the public nature of the wallboard encouraged greater commitment and updating. However, material tools fall short on several other dimensions such as distribution, complex dependency tracking, and versioning. We believe that some of the benefits of material tools should be incorporated into electronic systems and suggest design alternatives that could bring these benefits to electronic systems.
    Keywords: CSCW, Ethnography, Group work, Co-ordination, Group memory, Interpersonal communications, Media, Software development
    Recognition Accuracy and User Acceptance of Pen Interfaces BIBAKHTML 503-510
      Clive Frankish; Richard Hull; Pam Morgan
    The accuracy of handwriting recognition is often seen as a key factor in determining the acceptability of hand-held computers that employ a pen for user interaction. We report the results of a study in which the relationship between user satisfaction and recogniser performance was examined in the context of different types of target application. Subjects with no prior experience of pen computing evaluated the appropriateness of the pen interface for performing three different tasks that required translation of handwritten text. The results indicate that the influence of recogniser performance on user satisfaction depends on the task context. These findings are interpreted in terms of the task-related costs and benefits associated with handwriting recognition. Further analysis of recognition data showed that accuracy did not improve as subjects became more practised. However, substantial gains in accuracy could be achieved by selectively adapting the recogniser to deal with a small, user-specific subset of characters.
    Keywords: Pen-based input, Handwriting recognition

    Design Briefings: Interfaces for Children

    Designing the PenPal: Blending Hardware and Software in a User-Interface for Children BIBAKHTML 511-518
      Philippe Piernot; Ramon M. Felciano; Roby Stancel; Jonathan Marsh; Marc Yvon
    As part of the 1994 Apple Interface Design Competition, we designed and prototyped the PenPal, a portable communications device for children aged four to six. The PenPal enables children to learn by creating images and sending them across the Internet to a real audience of friends, classmates, and teachers. A built-in camera and microphone allow children to take pictures and add sounds or voice annotations. The pictures can be modified by plugging in different tools and sent through the Internet using the PenPal Dock. The limited symbolic reasoning and planning abilities, short attention span, and pre-literacy of children in this age range were taken into account in the PenPal design. The central design philosophy and main contribution of the project was to create a single interface based on continuity of action between hardware and software elements. The physical interface flows smoothly into the software interface, with a fuzzy boundary between the two. We discuss the design process and usability tests that went into designing the PenPal, and the insights that we gained from the project.
    Keywords: Hardware and software integration, User-centered design for children, Internet and multimedia application, Educational application, Portable computing
    Amazing Animation: Movie Making for Kids BIBAKHTML 519-524
      Shannon L. Halgren; Tony Fernandes; Deanna Thomas
    The development of the interface for Amazing Animation was a challenging, unique, and a rewarding experience for our Interface Design Group at Claris. Given the constraints of a very tight timeframe and working with a user population we were unfamiliar with, our group was able to make numerous improvements which had a tremendous impact on the product's usability. This having been our first time designing for and testing children, we learned volumes about this unique user population. Design assumptions and testing methodologies used in adult products must all be reworked for kids. This paper describes the progression of Amazing Animation interface and points out the lessons learned about testing and designing for kids along the way.
    Keywords: Interface design, Kids software, Designing for children, Testing children

    Design Briefings: Redesigning Existing Products

    Drag Me, Drop Me, Treat Me Like an Object BIBAKHTML 525-530
      Annette Wagner; Patrick Curran; Robert O'Brien
    This design briefing covers the major human interface design issues encountered in the development of the Common Desktop Environment Drag and Drop Convenience Application Programming Interface. The presentation will walk through the icon development, user testing and the different problems and solutions that arose during development.
    Keywords: Computer-human interface, Direct manipulation, Drag and drop, Common Desktop Environment, Icons, Drag icons, Motif 1.2
    The Effects of Practical Business Constraints on User Interface Design BIBAKHTML 531-537
      Debra Hershmann
    In a business environment, resource, budget and schedule constraints profoundly affect a product's user interface design. This paper describes the design of a graphical workflow application as it was affected by compromise between management, design and development during the product life cycle.
       The product is tracked from its initial implementation as a highly functional utility with a non-standard user interface, to its brief life as a prototype representing the ultimate workflow tool. Primary focus is on the third, most recent version, and the design problems that arose in delivering a highly usable interface within practical, real world constraints.
    Keywords: Iterative design, Resource constraints, Compromise, Prototyping, Usability testing

    Design Briefings: Managing Complex Data

    Replacing a Networking Interface "From Hell" BIBAKHTML 538-545
      Roxanne F. Bradley; Linn D. Johnk
    A multidisciplinary design team at Hewlett-Packard (HP) has successfully designed a new user interface for a network troubleshooting tool. Users felt that the new interface let them focus on the task of network troubleshooting, thus freeing them from the details of the interface and its underlying implementation. The design team believes that the success achieved is due to the process used and the multidisciplinary aspect of the team.
       This design review describes the process followed by the design team, the difficulties encountered, the results obtained from a comparative evaluation of the new and existing product interfaces, and the lessons learned.
    Keywords: User-centered design, Usability release criteria, Usability inspections, Comparative usability testing
    User-Centered Development of a Large-Scale Complex Networked Virtual Environment BIBAKHTML 546-552
      Thomas W. Mastaglio; Jeanine Williamson
    An integrated development team comprised of industry engineers, government engineers, and user community representatives is developing a large-scale complex networked virtual environment for the United States Army. The effort is organized into concurrent engineering teams responsible for each system component. Prototypical users who are formally called a User Optimization Team are an integral part of the development effort. The system under development is the Close Combat Tactical Trainer (CCTT). It is comprised of a network of simulators and workstations which interface with a virtual environment representing real world terrain. The nature of these systems requires user involvement in all phases of systems engineering, software development, and testing. The development organization and the usability engineering approaches used are mosaics of engineering skills, knowledge and HCI techniques.
    Keywords: User-centered development, User evaluations, User optimization team, Concurrent engineering, Integrated development, Spiral system development

    Design Briefings: Interfaces for Communication

    Neither Rain, Nor Sleet, Nor Gloom of Night: Adventures in Electronic Mail BIBAKHTML 553-557
      Maria Capucciati; Patrick Curran; Kimberly Donner O'Brien; Annette Wagner
    This Design Briefing tells the story of the design and implementation of Mailer, an electronic mail application being built as part of the Common Desktop Environment, a UNIX-based desktop. The design is notable in that it incorporates past usability data, new toolkit widgets, and compliance with a user interface style that was being written at the time the interface was being designed. In addition, Mailer is the product of a collaborative effort within and across companies, where the design is orchestrated among software developers, human interface engineers, and technical writers across the hall and across the country.
    Keywords: User interface design, Electronic mail, Design collaboration, Common Desktop Environment
    The Interchange Online Network: Simplifying Information Access BIBAKHTML 558-565
      Ron Perkins
    The AT&T Interchange Online Network is an online service designed to foster a sense of community while making it easy for customers to find information. This briefing describes how numerous design iterations aided by usability testing led to progressive refinement of the interface, specifically the information space layout for navigation. By combining context and content, Interchange allows orientation in a large information space. It becomes possible to understand all that is contained in a specific area at a glance. One design goal was to leverage editorial expertise while simultaneously taking advantage of publishing models extended to a very large online information space. Our overriding objective was to create an elegant, modern, and professional information service that values the time of busy people. Testing showed that even people who had never used an online service successfully navigated the large information space and enjoyed using Interchange. At the time of this writing, Interchange is at a Beta test stage and the design may be modified by the time the briefing is presented.
    Keywords: On-line service, Information design, Information space, Electronic publishing, Hypertext, Hypermedia, Interface design, Usability testing, Information retrieval

    Design Briefings: Designing with Metaphors

    Articulating a Metaphor through User-Centered Design BIBAKHTML 566-572
      H. J. Moll-Carrillo; Gitta Salomon; Matthew Marsh; Jane Fulton Suri; Peter Spreenberg
    TabWorks book metaphor enhances the standard Windows user interface, providing an alternative way to organize applications and documents in a familiar, easy to use environment. The TabWorks interface was designed collaboratively by IDEO and XSoft and was based on a concept developed at Xerox PARC. This briefing describes how a user-centered approach affected the design of the TabWorks user interface: how the metaphor's visualization evolved and how interaction mechanisms were selected and designed.
    Keywords: User-centered design, Design process, Product design, User observation, Metaphor, Book, Tab, Application, Document, Container
    Designing a "Front Panel" for Unix: The Evolution of a Metaphor BIBAKHTML 573-579
      Jay Lundell; Steve Anderson
    The Front Panel component of the Common Desktop Environment is a culmination of several year's effort in designing a "dashboard-like" element for graphical Unix desktop systems. This design was a cooperative effort between graphic design artists, human factors professionals, and software designers, and eventually became a cross-company effort as it was adopted for the Common Desktop Environment. We describe the processes that emerged to support this design, and make observations about how metaphors may evolve over time.
    Keywords: Metaphor, Front panel, Software design, Visual design, Workspaces, Dashboard