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CHI Tables of Contents: 8182838586878889909192X

Proceedings of ACM CHI'94 Conference on Human Factors in Computing Systems

Fullname:Companion of CHI'94 Conference on Human Factors in Computing Systems
Note:Celebrating Interdependence
Editors:Catherine Plaisant
Location:Boston, Massachusetts
Dates:1994-Apr-24 to 1994-Apr-28
Volume:2
Publisher:ACM
Standard No:ACM ISBN 0-89791-651-4 ACM ISSN 0713-5424; ACM Order Number 608941; ACM DL: Table of Contents hcibib: CHI94-2
Pages:488
  1. CHI 1994-04-24 Volume 2
    1. PAPER ABSTRACTS: Design in the Workplace
    2. PAPER ABSTRACTS: Accessing and Exploring Information
    3. PAPER ABSTRACTS: Supporting Distributed Work
    4. PAPER ABSTRACTS: Multimedia in Use
    5. PAPER ABSTRACTS: Expressive Interfaces
    6. PAPER ABSTRACTS: Multimedia Interfaces
    7. PAPER ABSTRACTS: Active Support for Interaction
    8. PAPER ABSTRACTS: Studies of Communication and Cooperative Work
    9. PAPER ABSTRACTS: Tools for Design
    10. PAPER ABSTRACTS: Auditory Information Interfaces
    11. PAPER ABSTRACTS: Accessing and Using Stored Documents
    12. PAPER ABSTRACTS: Social Aspects of Design
    13. PAPER ABSTRACTS: Designing Spoken Language Systems
    14. PAPER ABSTRACTS: Automatic Support in Design and Use
    15. PAPER ABSTRACTS: Evaluation Methods
    16. PAPER ABSTRACTS: Pen Input
    17. PAPER ABSTRACTS: HCI Research?
    18. PAPER ABSTRACTS: Design Evaluation
    19. PAPER ABSTRACTS: Information Visualization
    20. PAPER ABSTRACTS: Access to Organized Data Structures
    21. PAPER ABSTRACTS: GOMS Analysis
    22. PAPER ABSTRACTS: Visual Interaction Techniques
    23. PAPER ABSTRACTS: Designing Interaction Objects
    24. PAPER ABSTRACTS: HCI in the Real World
    25. PAPER ABSTRACTS: Evaluating Pointing Devices
    26. PAPER ABSTRACTS: Analysis of Programming Environments
    27. PAPER ABSTRACTS: Cognitive Models
    28. PAPER ABSTRACTS: Interacting in 3-D

CHI 1994-04-24 Volume 2

PAPER ABSTRACTS: Design in the Workplace

Scandinavian Design: Users in Product Development BIBAKPDF 199
  Morten Kyng
This paper presents an approach to user involvement in product development that has grown out of a Scandinavian tradition for cooperation with end-users in design. This tradition emphasizes early and continuing end-user involvement, and has over the last decade been applied successfully in several projects. Most of these projects have, however, been research projects or of the type in-house or contract development, and the claim is often made that this way of involving users is not suited for product development. In this paper I sketch the ideas behind involving users in the design process, and then present and discuss a case of product development in the CSCW area, where more traditional development activities were integrated with intensive cooperation with end-users.
Keywords: Cooperative design, Participatory design, Product development, Computer supported cooperative work
Designing Workscape: An Interdisciplinary Experience BIBAKPDF 199
  Joseph M. Ballay
Workscape is a clean-slate design for an office document management product. It was developed through a unique collaboration among the staffs of Digital and MAYA. From earliest concepts to current refinements and productization, Workscape has benefited from interdisciplinary design methods involving specialists from the fields of human factors, computer science, and visual design. Extensive use of mockups, in a variety of media, proved particularly effective in bridging differences of terminology and methodology between these three disciplines.
Keywords: Design, Documents, Interdisciplinary

PAPER ABSTRACTS: Accessing and Exploring Information

An Improved Interface for Tutorial Dialogues: Browsing a Visual Dialogue History BIBAKPDF 200
  Benoit Lemaire; Johanna Moore
When participating in tutorial dialogues, human tutors freely refer to their own previous explanations. This paper describes the design of a user interface for a tutoring system that enables both the system and the user to refer to the past dialogue. The work is based on the notion that the dialogue history is a source of knowledge that can be manipulated like any other. In particular, we describe an interface that allows students to visualize the dialogue history on the screen, highlight its relevant parts and query and manipulate the dialogue history.
Keywords: Tutorial interactions, Dialogue history, Information visualization
Using Aggregation and Dynamic Queries for Exploring Large Data Sets BIBAKPDF 200
  Jade Goldstein; Steven F. Roth
We have categorized user goals for exploring large data sets into three classes: data manipulation, data analysis, and data visualization. Data manipulation goals, which involve the selection and transformation of data prior to viewing, consist of three main types: scope goals (for selecting the amount of data), focus of attention goals (for selecting relevant attributes), and level of detail goals (for aggregating and decomposing data groups). Using this classification, we evaluate existing data manipulation techniques and integrate two synergistic interface mechanisms, the Aggregate Manipulator and Dynamic Query. We demonstrate how they successfully achieve data manipulation goals for real estate sales data.
Keywords: Interactive techniques, Data exploration, Data visualization, Large data sets, Graphics presentation, Intelligent interfaces
An Image Retrieval System Considering Subjective Perception BIBAKPDF 201
  Haruhiko Nishiyama; Sumi Kin; Teruo Yokoyama; Yutaka Matsushita
The human interface plays an important role in an information retrieval system. Visual information is a good human-machine communication system. This paper proposes an image retrieval scheme based on the assumption that end-users make use of image database systems. When a human being looks at graphical materials such as artistic paintings, he/she memorizes them using two patterns in his/her visual memory: the first pattern is that of looking roughly at the whole image, the second is that of paying attention to specific objects such as a person or a desk.
Keywords: Image database, Subjective perception, Graphical user interface, Spatial relationship, Image expression model, Visual language

PAPER ABSTRACTS: Supporting Distributed Work

Montage: Providing Teleproximity for Distributed Groups BIBAKPDF 201
  John C. Tang; Monica Rua
Montage is a research prototype that explores using video to help collaborators find opportune times to interact with each other and to provide a sense of teleproximity. Montage uses momentary, reciprocal glances among networked workstations to make it easy to peek into someone's office. From a glance, users can quickly start a full-featured desktop video conference. If the person is not there, Montage provides quick access to browse her on-line calendar, send her email, or send her an electronic note that pops up on her screen. Preliminary usage data shows that users did use Montage to have short, lightweight interactions.
Keywords: Awareness, Remote collaboration, Media spaces, Video, Computer-supported cooperative work
Courtyard: Integrating Shared Overview on a Large Screen and Per-User Detail on Individual Screens BIBAKPDF 202
  Masayuki Tani; Masato Horita; Kimiya Yamaashi; Koichiro Tanikoshi; Masayasu Futakawa
The operation of complex real-world systems requires that multiple users cooperate in monitoring and controlling large amounts of information. The Courtyard system supports such cooperative work by integrating an overview on a shared large display and per-user detail on individual displays. Courtyard allows a user to move a mouse pointer between the shared and individual screens as though they were contiguous, and to access per-user detailed information on the user's individual display simply by pointing to an object on the shared display. Courtyard selects the detailed information according to the tasks assigned to the pointing user.
Keywords: Computer-supported cooperative work, Shared large display, Per-user detail
Distributed Collaborative Writing: A Comparison of Spoken and Written Modalities for Reviewing and Revising Documents BIBAKPDF 202
  Christine M. Neuwirth; Ravinder Chandhok; Davida Charney; Patricia Wojahn; Loel Kim
Previous research indicates that voice annotation is valuable for expressing the more complex and social aspects of a collaborative writing task. No direct evidence exists, however, about the effect of voice annotations on the recipients. To test this, we designed an interface intended to alleviate some of the problems associated with voice output and undertook a study with two goals: to compare the nature and quantity of voice and written comments, and to evaluate how writers responded to comments produced in each mode. This study provides direct evidence that the voice modality produces usable annotations and yields user interface insights.
Keywords: Computer-supported cooperative work, Collaborative writing, Annotations, Voice

PAPER ABSTRACTS: Multimedia in Use

Marquee: A Tool for Real-Time Video Logging BIBAKPDF 203
  Karon Weber; Alex Poon
We describe Marquee, a pen-based video logging tool which enables users to correlate their personal notes and keywords with a videotape during recording. We present our observations about coordinating the task of logging in real time and describe the three phases, user-centered approach we took in designing the tool. Our early work explored the functionalities needed by users to successfully create a log. In the second phase we focused on testing our intuitions about logging by conducting user studies with paper mock-ups. In the final phase, we implemented a working prototype system and placed it in a setting to see if it supported people logging in real time.
Keywords: Video indexing, Video annotation, Gestural interfaces, Penbased computing, User interfaces, User studies, Multimedia
A Comparison of the Use of Text and Multimedia Interfaces to Provide Information to the Elderly BIBAKPDF 203
  Virginia Z. Ogozalek
This report describes an experiment in which 64 elderly participants, average age 71, used (1) a text-only or (2) a multimedia computer interface to obtain information-in this case, about prescription drugs. The participants, none of whom had used a computer before, compared the computerized information systems to a more traditional "interface" of words printed on paper. Results indicate that, for this group of elders, who were recruited from a seniors' group at a college, a multimedia presentation was better than a text-only screen or a printed leaflet, on both performance and preference measures.
Keywords: Multimedia, Elderly users, Health care, Information search and retrieval, Interactive video, User interface, Aging, User study, Computers and medicine

PAPER ABSTRACTS: Expressive Interfaces

Computers Are Social Actors BIBAKPDF 204
  Clifford Nass; Jonathan Steuer; Ellen R. Tauber
This paper presents a new experimental paradigm for the study of human-computer interaction. Five experiments provide evidence that individuals' interactions with computers are fundamentally social. The studies show that social responses to computers are not the result of conscious beliefs that computers are human or human-like. Moreover, such behaviors do not result from users' ignorance or from psychological or social dysfunctions, nor from a belief that subjects are interacting with programmers. Rather, social responses to computers are commonplace and easy to generate. The results reported here present numerous and unprecedented hypotheses, unexpected implications for design, new approaches to usability testing, and direct methods for verification.
Keywords: Anthropomorphism, Agents, Voice, Speech, Social psychology, Gender, Design
Form-Giving: Expressing the Nonobvious BIBAKPDF 204
  Gerda Smets; Kees Overbeeke; William Gaver
The design of richly informative interfaces would benefit from an account of how visual forms convey information. In this paper we suggest that the study of form-giving in Industrial Engineering might provide a foundation for such an account. We present three studies of designed synesthesia, in which objects' forms indicate non-visible attributes such as taste or smell. These studies illustrate the rich possibilities for conveying information with form, possibilities which are routinely exploited in industrial design. We believe that similar opportunities exist for interface design, and that further studies of form-giving may help in taking advantage of them. Results of a student exercise expressing computer metaphors in 3D forms will be discussed.
Keywords: Interface design, Visualization, Form-giving, Affordances, Ecological approaches
Using a Human Face in an Interface BIBAKPDF 205
  Janet H. Walker; Lee Sproull; R. Subramani
We investigated subjects' responses to a synthesized talking face displayed on a computer screen in the context of a questionnaire study. Compared to subjects who answered questions presented via text display on a screen, subjects who answered the same questions spoken by a talking face spent more time, made fewer mistakes, and wrote more comments. When we compared responses to two different talking faces, subjects who answered questions spoken by a stern face, compared to subjects who answered questions spoken by a neutral face, spent more time, made fewer mistakes, and wrote more comments. They also liked the experience and the face less. We interpret this study in the light of desires to anthropomorphize computer interface and suggest that incautiously adding human characteristics, like face, voice, and facial expressions, could make the experience for users worse rather than better.
Keywords: User interface design, Multimodal interfaces, Anthropomorphism, Facial expression, Facial animation, Personable computers

PAPER ABSTRACTS: Multimedia Interfaces

Designing Presentation in Multimedia Interfaces BIBAKPDF 205
  Alistair Sutcliffe; Peter Faraday
Current Multimedia interfaces are created primarily by intuition. Development of a method for analysis and design of Multimedia presentation interfaces is described. The study investigates task based information analysis, persistence of information, selective attention and concurrency in presentation. The method gives an agenda of issues, diagrams and techniques for specifications, and guidelines for media selection and presentation scripting. Use of the method is illustrated with an example from a shipboard emergency management system.
Keywords: Multimedia, Design guidelines, Methodology
The "Starfire" Video Prototype Project: A Case History BIBAKPDF 206
  Bruce Tognazzini
Developing a new working computer system can now cost hundreds of millions of dollars, all expended at great risk. Company managers who must take responsibility for making development decisions are loath to do so without being able to see and understand the system they will be "buying." When Sunsoft launched the Starfire project to develop a next-generation interface, we turned to video prototyping, in the form of a short 35 mm film delivered in video. Not only were we thus able to show in mature form many key specifics of our new interface design, but we were able to communicate a strong sense of the resulting overall user experience. This paper describes observations and guidelines we developed during the early stages of the film, and what our experiences were in applying them.
Keywords: Film, Video, Video prototype, Prototype, Observation, Guideline, Drama, Story, Interaction, Gesture, Stylus, Mouse, Voice recognition, Anthropomorphic agent, Agent, Feedback, Social, Ethics, Privacy, Future

PAPER ABSTRACTS: Active Support for Interaction

Creating Charts by Demonstration BIBAKPDF 206
  Brad A. Myers; Jade Goldstein; Matthew A. Goldberg
"Gold" is a new interactive editor that allows a user to draw examples of the desired picture for business graphics and the system automatically produces a visualization. To specify a custom visualization in other systems, code must be written or a bewildering array of dialog boxes and commands must be used. In Gold, as the user is drawing an example of the desired visualization, knowledge of properties of the data and the typical graphics of business charts are used to generalize the example and create a picture for the actual data. The goal is to make designing a complex, composite chart almost as easy as sketching a picture on a napkin.
Keywords: Data visualization, Demonstrational interfaces, Interactive techniques, Business charts
Interactive Graphic Design Using Automatic Presentation Knowledge BIBAKPDF 207
  Steven F. Roth; John Kolojejchick; Joe Mattis; Jade Goldstein
Tools for creating data graphics are complex, require significant graphic expertise, and use predefined graphics that cannot integrate multiple data types. To solve these problems, we applied automatic data presentation capabilities to enable two interactive design tools. SageBrush enables users to assemble graphical sketches from primitives and partial prototypes. SageBook enables users to browse previously created pictures relevant to new data. SAGE, an automatic presentation system, supports these by completing underspecified designs, rendering unique graphic combinations, searching for relevant pictures, and redesigning old pictures to display new data. Our claim is that design interfaces must have automatic graphic knowledge to be effective.
Keywords: Graphic design, Data visualization, Automatic presentation systems, Intelligent interfaces, Design environments, Interactive techniques
Repeat and Predict -- Two Keys to Efficient Text Editing BIBAKPDF 207
  Toshiyuki Masui; Ken Nakayama
We demonstrate a simple and powerful predictive interface technique for text editing tasks. With our technique called the dynamic macro creation, when a user types a special "repeat" key after doing repetitive operations in a text editor, an editing sequence corresponding to one iteration is detected, defined as a macro, and executed at the same time. When we use another special "predict" key in addition to the repeat key, wider range of prediction schemes can be performed depending on the order of using these two keys.
Keywords: Text editing, Predictive interface, Programming by example, PBE, Programming by demonstration, PBD, Keyboard macro, Dynamic macro creation

PAPER ABSTRACTS: Studies of Communication and Cooperative Work

Communicating About Communicating: Cross-Disciplinary Design of a Media Space Interface BIBAKPDF 208
  Beverly Harrison; Marilyn Mantei; Garry Beirne; Tracy Narine
This paper describes benefits and misunderstandings resulting from differing perspectives and methodologies in a cross-disciplinary team. Our team designed and deployed a media space (video communication system). The interface designers were frustrated by the limited user access and rigid schedules necessary for the sociologists. The sociologists saw designers as non-observant researchers using invasive research practices and inconstant measures. In the end, both disciplines helped the other accomplish their goals. The sociologists learned something about evaluating technology and how usability impacts future product acceptance. The designers learned how detailed studies of current work practices and roles can provide design clues.
Keywords: User interface design, Inter-disciplinary, Sociology, Video, Media space, Videoconferencing
Informal Workplace Communication: What is It Like and How Might We Support It? BIBAKPDF 208
  Steve Whittaker; David Frohlich; Owen Daly-Jones
We present new findings about the nature of informal communications, derived from a naturalistic study of people's everyday working activities. We identify why such interactions are so common, and valuable and how they are achieved in the workplace. We also address weaknesses in current systems that support such interactions remotely and identify further requirements for better support. We also discuss the implications of this work for conversational theories.
Keywords: Informal communication, Audio, Video, CSCW, Workplace activity, Ethnography
A Room of Our Own: Experiences from a Direct Office Share BIBAKPDF 209
  Annette Adler; Austin Henderson
For nine months, the authors worked in a "direct office share" -- two offices joined by unswitched audio/video connections. This paper describes that experience. While working together, the authors were engaged in developing an architecture of use for techno-social systems-framework for describing distributed technology and people together at work. The paper therefore also seeks to achieve a second purpose: to present, mostly by demonstrating its use, the beginnings of such an architecture. This description comprises three complementary "sightings" on the direct office share, labeled 1, 1+1, and (1+1)+others. Each sighting captures selected aspects of technology (audio/video connections) in use by the authors at work. This capturing of experience demonstrates by example that multiple sightings provide a powerful form for describing techno-social systems, that current patterns of use both support and interfere with the use of new technology, and that only in a description that encompasses both the technical and social can the use of technology be comprehended.
Keywords: Audio/video connections, Direct office share, Architecture of use, Technology in use, Descriptions of work

PAPER ABSTRACTS: Tools for Design

Methods in Search of Methodology -- Combining HCI and Object Orientation BIBAKPDF 209
  Susan McDaniel; Gary M. Olson; Judith S. Olson
Software design and user interface design and analysis methods are each insufficient methods for ensuring good software development. We propose a combination of object-oriented analysis and design, human computer interaction, and process redesign forged into one methodology. We describe the use of these methods in a project case study and conclude with a synopsis of how the methods worked and lessons we learned.
Keywords: Object-oriented methods, Human computer interaction, User-centered design, Business process redesign
Enhancing the Explanatory Power of Usability Heuristics BIBAKPDF 210
  Jakob Nielsen
Several published sets of usability heuristics were compared with a database of existing usability problems in order to determine what heuristics best explain actual usability problems. Based on a factor analysis of the explanations as well as an analysis of the heuristics providing the broadcast explanatory coverage of the problems, a new set of nine heuristics were derived: visibility of system status, match between system and real world, user control and freedom, consistency and standards, error prevention, recognition rather than recall, flexibility and efficiency of use, aesthetic and minimalist design, and helping users recognize, diagnose, and recover from errors.
Keywords: Discount usability engineering, Heuristic evaluation, Usability problems
Development and Evaluation of a Model of Behavioral Representation Techniques BIBAKPDF 210
  J. D. Chase; Robert S. Schulman; H. Rex Hartson; Deborah Hix
A user-centered approach to interactive system development requires a way to represent the behavior of a user interacting with an interface. While a number of behavioral representation techniques exist, not all provide the capabilities necessary to support the interaction development process. We have developed a taxonomical model of behavioral representation techniques. Our model is an epistemological framework for analyzing and comparing existing behavioral representation techniques, as well as developing and evaluating new techniques. We present the model and results of our evaluation demonstrating the model's reliability and utility within the context of behavioral representation techniques.
Keywords: Usability, Behavioral representation techniques, Interaction development, Model, Empirical evaluation

PAPER ABSTRACTS: Auditory Information Interfaces

Nonvisual Presentation of Graphical User Interfaces: Contrasting Two Approaches BIBAKPDF 211
  Elizabeth D. Mynatt; Gerhard Weber
Users who are blind currently have limited access to graphical user interfaces based on MS Windows or X Windows. Past access strategies have used speech synthesizers and braille displays to present text-based interfaces. Providing access to graphical applications creates new human interface design challenges which must be addressed to build intuitive and efficient nonvisual interfaces. Two contrasting designs have been developed and implemented in the projects Mercator and GUIB. These systems differ dramatically in their approaches to providing nonvisual interfaces to GUIs. This paper discusses four main interface design issues for access systems, and describes how the Mercator and GUIB designs have addressed these issues. It is hoped that the exploration of these interfaces will lead to better nonvisual interfaces used in low visibility and visually overloaded environments.
Keywords: Nonvisual HCI, Blind users, Graphical user interfaces, Auditory interfaces, Tactile interfaces
The Design and Evaluation of an Auditory-Enhanced ScrollBar BIBAKPDF 211
  Stephen A. Brewster; Peter C. Wright; Alistair D. N. Edwards
A structured method is described for the analysis of interactions to identify situations where hidden information may exist and where non-speech sound might be used to overcome the associated problems. Interactions are considered in terms of events, status and modes to find any hidden information. This is then categorised in terms of the feedback needed to present it. An auditory-enhanced scrollbar, based on the method described, was then experimentally tested. Timing and error rates were used along with subjective measures of workload. Results from the experiment show a significant reduction in time to complete one task, a decrease in the mental effort required and an overall preference for the auditory-enhanced scrollbar.
Keywords: Auditory interfaces, Multi-modal interface, Earcons, Sonification, Auditory-enhanced widgets

PAPER ABSTRACTS: Accessing and Using Stored Documents

Protofoil: Storing and Finding the Information Worker's Paper Documents in an Electronic File Cabinet BIBAKPDF 212
  Ramana Rao; Stuart K. Card; Walter Johnson; Leigh Klotz; Randy Trigg
Although the document imaging industry has taken off in the last few years, document image filing for the individual information worker is still not widespread or effective. In this paper, we focus on building an electronic filing system for paper documents that supports the ad hoc, multifarious work of information workers. Motivated by interviews with researchers and a survey of descriptive studies of paper document filing, we have focused on minimizing or delaying costs of document filing and supporting a rich variety of methods for assessing and using stored documents. We have implemented a prototype system called Protofoil for storing, retrieving, and manipulating paper documents as electronic images that integrates many user interface -- paper and workstation -- and information retrieval technologies. Protofoil has been tested through use in our laboratory, and has been deployed in a field study at a lawyer's office.
Keywords: Document imaging, Paper user interface, Information retrieval, Filing of paper documents, Ad hoc information work
The Marks are on the Knowledge Worker BIBAKPDF 212
  Alison Kidd
A study of knowledge workers showed that the most important thing about them is they are changed by information. They do not carry much written material with them, rarely consult files, and have cluttered desks. My explanation is that once informed, knowledge workers do not need to retain the information source. However, until informed, they cannot file information because they cannot categorise it. I conclude that the valuable marks are on knowledge workers rather than on paper or file and suggest that they might be better supported by improving the act of informing rather than storing information for them in a "disembodied" form.
Keywords: Knowledge workers, Information appliances, Writing, Memory

PAPER ABSTRACTS: Social Aspects of Design

Raison d'Etre: Capturing Design History and Rationale in Multimedia Narratives BIBAKPDF 213
  John M. Carroll; Sherman R. Alpert; John Karat; Mary S. Van Deusen; Mary Beth Rosson
Raison d'Etre is a hypermedia design history application. It provides access to a database of video clips containing stories and personal perspectives of design team members recorded at various times through the course of a project. The system is intended to provide a simple framework for recording and organizing the informal history and rationale that design teams create and share in the course of their collaboration. This paper describes (1) the scenarios of use we are trying to support, (2) the methods we used collecting and organizing the database, and (3) the status of our prototype.
Keywords: Documentation, Design history, Collaboration, Multimedia database, Hypermedia
Facilitating Effective HCI Design Meetings BIBAKPDF 213
  John L. Bennett; John Karat
Over several years we have participated as facilitators in many Human-Computer Interaction (HCI) design meetings. Our focus has been on developing team results needed to achieve user-centered design of software for computer systems. We describe frameworks for partnerships, stages of meetings, and team conversations that we have found useful. In order to illustrate our general approach, we select one design meeting experience as a case study. We close with observations on how facilitation skills might be developed by design team participants. This is needed in response to an emerging requirement for effective collaborative teamwork in HCI design activities.
Keywords: Methodologies, Design, Software engineering, Design process, Group work

PAPER ABSTRACTS: Designing Spoken Language Systems

Interface Techniques for Minimizing Disfluent Input to Spoken Language Systems BIBAKPDF 214
  Sharon Oviatt
This research examines spontaneous spoken disfluencies during human-computer interaction, presents a predictive model accounting for their occurrence, and outlines interface techniques for minimizing disfluent input. Data were collected during two studies in which people spoke to a highly interactive simulated system. Two factors were associated with an increase in speech disfluency rates: lengthiness of utterance, and lack of structure in the presentation format. In these studies, structural changes to the presentation format eliminated 70% of all disfluent speech. The long-term goal of this research is to provide empirical guidance for the design of robust spoken language technology.
Keywords: Speech disfluency, Predictive modeling, Interface design, Spoken language systems, Robust processing
An Object-Oriented Approach to Dialogue Management in Spoken Language Systems BIBAKPDF 214
  Randall Sparks; Lori Meiskey; Hans Brunner
We describe an object-oriented approach to dialog management for the design of spoken language interface to information services. In this approach, dialog states are abstract objects that encapsulate the information and behavior the system needs to interact successfully with the user at any given point in an extended dialog. An inheritance hierarchy determines the properties of particular dialog states, which are instantiated dynamically during the user-system dialog. Dialog management rules are methods that respond to different types of user inputs in a manner appropriate for the current dialog state. This approach has been used to implement a prototype of a telephone-based information service.
Keywords: Dialog management, Spoken language system, Object-oriented design, User interface

PAPER ABSTRACTS: Automatic Support in Design and Use

Automatic Generation of Interactively Consistent Search Dialogs BIBAKPDF 215
  Dan R., Jr. Olsen; Walter Holladay
The problem of creating search dialogs which are consistent with normal user interface dialogs is posed. The ART user interface tool kit is presented. The features of top-down filtering of interactive events and the modeling of interactor semantics as editing variables are discussed. Two special interactor filters are described which when wrapped around an editing dialog will transform that dialog into one which edits search patterns for the same class of objects.
Keywords: User interface, Tool-kits, Searching, Automatic transformation
Automatic Generation of Help from Interface Design Models BIBAKPDF 215
  Roberto Moriyon; Pedro Szekely; Robert Neches
Model-based interface design can save substantial effort in building help systems for interactive applications by generating help automatically from the model used to implement the interface, and by providing a framework for developers to easily refine the automatically-generated help texts. This paper describes a system that generates hypertext-based help about data presented in application displays, commands to manipulate data, and interaction techniques to invoke commands. The refinement component provides several levels of customization, including programming-by-example techniques to let developers edit directly help windows that the system produces, and the possibility to refine help generation rules.
Keywords: Automatic help generation, Model-based interface design, Hypertext-based help, Help customization, Help generation rules
Automating Interface Evaluation BIBAKPDF 216
  Michael D. Byrne; Scott D. Wood; Piyawadee "Noi" Sukaviriya; James D. Foley; David Kieras
One method for user interface analysis that has proven successful is formal analysis, such as GOMS. These methods have been criticized for being at minimum an additional burden for the system designer. However, if the process of constructing and using formal models could be automated, they could be of even greater value. This paper describes an early version of such a system, called USAGE. Given the application model necessary to drive the UIDE system, USAGE generates an NGOMSL model of the interface which can be "run" on a typical set of user tasks and provide execution and learning time estimates.
Keywords: GOMS, Usability, User interface design environment, Interface evaluation, Formal models of the user, UIMS

PAPER ABSTRACTS: Evaluation Methods

The Cost-of-Knowledge Characteristic Function: Display Evaluation for Direct-Walk Dynamic Information Visualizations BIBAKPDF 216
  Stuart K. Card; Peter Pirolli; Jock D. Mackinlay
In this paper we present a method, the Cost-of-Knowledge Characteristic Function, for characterizing information access from dynamic displays. The paper works out this method for a simple, but important, class of dynamic displays called direct-walk interactive information visualizations, in which information is accessed through a sequence of mouse selections and key selections. The method is used to characterize a simple calendar task for an application of the Information Visualizer, to compute the changes in characterization as the result of possible program variants, and to conduct empirical comparison between different systems with the same function.
Keywords: Information visualization, Dynamic displays, Methodology, Evaluation, 3D user interfaces, Information Visualizer
Comparative Usability Evaluation: Critical Incidents and Critical Threads BIBAKPDF 217
  Jurgen Koenemann-Belliveau; John M. Carroll; Mark K. Singley
Empirical usability evaluations (particularly formative evaluations) hinge on observing and interpreting critical incidents of use. We proposed augmenting critical incident methods by analysis of what we called critical threads: sets of causally related user episodes that, taken together, define major usability themes. This paper extends this work to the comparative usability analysis of a related artifact. We discuss how our earlier claims analysis was used to orient and simplify our current evaluation efforts.
Keywords: User interfaces, Evaluation methodology, Formative evaluation, Usability evaluation
Usability Testing in the Field: Bringing the Laboratory to the User BIBAKPDF 217
  David E. Rowley
Usability testing is not always best accomplished within the confines of a specifically equipped usability laboratory. Logistics and resource constraints sometimes necessitate taking the testing out on the road. This paper describes some of the issues surrounding a field testing program, and gives suggestions about how such an undertaking can be accomplished under strict financial, resource and schedule limitations. A case study is presented to help illustrate the planning and evaluation process, and to provide insights into the types of problems such an endeavor is likely to encounter, as well as some valuable lessons learned along the way.
Keywords: Usability testing, Formative evaluation, Field testing, Cooperative evaluation

PAPER ABSTRACTS: Pen Input

User Learning and Performance with Marking Menus BIBAKPDF 218
  Gordon Kurtenbach; William Buxton
A marking menu is designed to allow a user to perform a menu selection by either popping-up a radial (or pie) menu, or by making a straight mark in the direction of the desired menu item without popping-up the menu. This paper reports on a case study of user behavior with marking menus in a real work situation. The study demonstrates that when users become expert, marks are used extensively and are on average 3.5 times faster than using the menu. However, expert users still occasionally switch back to menus to refresh their memory of menu layout.
Keywords: Marking menus, Pie menus, Gestures, Pen based input, Accelerators, Input devices, Multimedia
T-Cube: A Fast, Self-Disclosing Pen-Based Alphabet BIBAKPDF 218
  Dan Venolia; Forrest Neiberg
An interface for entering text to a pen-based computer is described. The technique proposes a new alphabet, where each letter is a flick gesture. These flick gestures are self-disclosing using pie menus. An experiment determined the speeds of executing the flick gestures and the transition speeds between gestures. An assignment of characters to gestures is developed and evaluated. Audio feedback is used to convey whether a gesture was well- or badly-formed. A longitudinal study showed clear progress on a learning curve. The method is compared to soft keyboards, handwriting recognition systems, and unistrokes.
Keywords: Stylus, Text entry, Pen-based computing, Audio feedback
Filochat: Handwritten Notes Provide Access to Recorded Conversations BIBAKPDF 219
  Steve Whittaker; Patrick Hyland; Myrtle Wiley
We present a novel application which integrates handwriting and recorded audio in a semi-portable device. Based on user interviews, it allows people to straightforwardly access particular points in recorded spontaneous speech via handwritten notes, using temporal indexing. Laboratory studies showed objective benefits of combined notes and audio over notes alone. The utility of the access method was shown by improved performance over current audio technology such as dictaphones. We also found perceived benefits of higher quality meeting minutes in field trials. An unforeseen benefit was the use of this device as an audio editing tool. We discuss further technical extensions and user issues in relation to the prototype.
Keywords: Audio, "Speech-as-data", Retrieval, Handwriting, Notes, Indexing

PAPER ABSTRACTS: HCI Research?

A Preliminary Analysis of the Products of HCI Research, using Pro Forma Abstracts BIBAKPDF 219
  William Newman
A classification scheme for the products of engineering research is described, involving three principal categories: improved modelling techniques, solutions and tools. A set of pro forma abstracts are proposed as a means of identifying the three categories, and are found to cover over 90 percent of the 554 engineering papers sampled. However only 30 percent of papers published at recent CHI and INTERCHI conferences can be thus categorized. The remainder appear mostly to describe radical solutions (solutions not derived from incremental improvements to solutions to the same problem), and experience and/or heuristics gained mostly from studies of radical solutions.
Keywords: Human-computer interaction, Research methods, Research products, System design, Abstracts, Radical solutions

PAPER ABSTRACTS: Design Evaluation

Supporting Knowledge-Base Evolution with Incremental Formalization BIBAKPDF 220
  Frank M., III Shipman; Raymond McCall
Computers require formally represented information to support users but users often cannot provide it. This paper looks at an approach called "incremental formalization", when users express information informally and the system supports them in formalizing it. Incremental formalization requires a system architecture that can integrate formal and informal representations and enable and support moving information upward in formality. The system should include tools to capture naturally available informal information and knowledge-based techniques to suggest possible formalizations of this informal information. The Hyper-Object Substrate, a system with these characteristics, has been applied to a variety of domains.
Keywords: Formalization, Structure, Hypermedia, Knowledge-based systems, Knowledge representation, Knowledge acquisition
Seeding, Evolutionary Growth and Reseeding: Supporting the Incremental Development of Design Environments BIBAKPDF 220
  Gerhard Fischer; Ray McCall; Jonathan Ostwald; Brent Reeves; Frank Shipman
We describe an approach to acquiring information during the creation and use of domain-oriented environments. Our model consists of three phases: seeding, evolutionary growth, and reseeding. A seed for a domain-oriented design environment is created through a participatory design process between environment developers and domain designers by incorporating domain-specific knowledge into a domain-independent architecture for design environments. Evolutionary growth takes place as domain designers use the seeded environment to undertake specific projects. Reseeding is a process that reinvolves the environment developers to help domain designers better organize, formalize, and generalize knowledge added during the use phases.
Keywords: Design, Design environments, Domain-orientation, Evolution of information spaces, Seeds, Reseeding, Annotation, Incremental formalization, Tacit knowledge, Situated cognition, End-user modifiability, Collaborative design
Talking Through Design: Requirements and Resistance in Cooperative Prototyping BIBAKPDF 221
  John Bowers; James Pycock
Some analyses are presented of talk between designers and a potential user in a participatory design session where a prototype application was worked with to determine future requirements. We explore the ways in which design suggestions are formulated and argued for, and how requirements emerge as a negotiated product of interaction. On this basis, we re-examine user participation in design and the relationship between prototyping and user requirements. We conclude by offering a notion (gradients of resistance in design space) to help understanding the interplay of the social and the technical in design.
Keywords: Requirements, Participatory design, Interaction analysis

PAPER ABSTRACTS: Information Visualization

The Movable Filter as a User Interface Tool BIBAKPDF 221
  Maureen C. Stone; Ken Fishkin; Eric A. Bier
Magic Lens filters are a new user interface tool that combine an arbitrarily-shaped region with an operator that changes the view of objects viewed through that region. These tools can be interactively positioned over on-screen applications much as a magnifying glass is moved over a newspaper. This paper describes their advantages in more detail and illustrates them with examples of magic lens filters in use over a variety of applications.
Keywords: Viewing filter, Lens, Transparent, Visualization, Editing, Macro, Graphics
Visual Information Seeking: Tight Coupling of Dynamic Query Filters with Starfield Displays BIBAKPDF 222
  Christopher Ahlberg; Ben Shneiderman
Visual information seeking (VIS) is distinguished from familiar query composition and information retrieval because of its emphasis on rapid filtering, progressive refinement or search parameters, continuous reformulation of goals, and visual scanning to identify results. VIS principles developed: dynamic query filters (query parameters rapidly adjust with sliders, buttons, maps, etc.), starfield displays (two-dimensional scatterplots to structure result sets), and tight coupling (interrelating query components to preserve display invariants and support progressive refinement and an emphasis on using search output to foster search input). A FilmFinder prototype using a movie database demonstrates these principles.
Keywords: Database query, Dynamic queries, Information seeking, Tight coupling, Starfield displays
The Table Lens: Merging Graphical and Symbolic Representations in an Interactive Focus+Context Visualization for Tabular Information BIBAKPDF 222
  Ramana Rao; Stuart K. Card
We present a new visualization, called the Table Lens, for visualizing and making sense of large tables. The visualization uses a focus+context (fisheye) technique that works effectively on tabular information because it allows display of crucial label information and multiple distal focus areas. In addition, a graphical mapping scheme for depicting table contents has been developed for the most widespread kind of tables, the case-by-variables table. The Table Lens fuses symbolic and graphical representations into a single coherent view that can be fluidly adjusted by the user. This fusion and interactivity enables an extremely rich and natural style of direct manipulation exploratory data analysis.
Keywords: Information visualization, Exploratory data analysis, Graphical representations, Focus+context technique, Fisheye technique, Tables, Spreadsheets, Relational tables

PAPER ABSTRACTS: Access to Organized Data Structures

Evaluating the Influence of Interface Styles and Multiple Access Paths in Hypertext BIBAKPDF 223
  Pawan R. Vora; Martin G. Helander; Valerie L. Shalin
In this paper, we investigated usability issues in hypertext. First, we compared usability of graphical and textual interfaces. The results favored a graphical interface with labeled links (GL). However, subjects suggested incorporating multiple pathways to facilitate search. To determine how hypertext designers could establish, a priori, multiple structures, we consulted domain experts. Distinct organizations emerged from experts in different professions. Therefore, we modified the hypertext to incorporate these multiple structures. On subsequent evaluation, contrary to previous evidence, multiple structures enhanced search performance. Based on these experiments, we recommend using a GL interface and multiple semantic organizations to improve hypertext usability.
Keywords: Hypertext, Usability, Design guidelines, Graphical vs. textual interfaces, Single vs. multiple organizations, Expert organizations
Multitrees: Enriching and Reusing Hierarchical Structure BIBAKPDF 223
  George W. Furnas; Jeff Zacks
This paper introduces multitrees, a new type of structure for representing information. Multitrees are a class of directed acyclic graphs (DAGs) with the unusual property that they have large easily identifiable substructures that are trees. These subtrees have a natural semantic interpretation providing alternate hierarchical contexts for information, as well as providing a natural model for hierarchical reuse. The numerous trees found within multitrees also afford familiar, tree-based graphical interactions.
Keywords: Information graphs, Representation, Hierarchies, Reuse, Directed graphs, Hypertext structures, Graphical browsers

PAPER ABSTRACTS: GOMS Analysis

A Keystroke Level Analysis of a Graphics Application: Manual Map Digitizing BIBAKPDF 224
  Peter Haunold; Werner Kuhn
Manually transforming analog graphic data, such as maps, into digital form is slow and expensive, but widely performed. The work reported here investigates the possibility to apply the Keystroke-Level Model to the modeling and optimization of manual map digitizing tasks. We tested the suitability of the model at a national mapping agency and determined unit tasks with their performance times. The paper describes an experiment to measure performance times under production conditions. Two new keystroke level operators are defined for manual digitizing. The use and suitability of the model are demonstrated by comparing predicted and measured performance times.
Keywords: Keystroke-level model, Graphics, Map digitizing, Geographic information systems, Interface design optimization
A GOMS Analysis of the Advanced Automated Cockpit BIBAKPDF 224
  Sharon Irving; Peter Polson; J. E. Irving
A GOMS analysis of a subset of skills needed to use the Flight Management Computer on advanced, commercial "glass-cockpit" aircraft revealed the existence of just three common methods, as well as inconsistencies in the interface. Novices given low-fidelity, part-task Macintosh computer based training in accordance with this formal modeling effort could carry out similar tasks in a full motion flight simulator, using real aircraft hardware. Their performance was compared with pilots who had just completed professional training as well as with experts. Their performance of all groups reflected difficulties with the interface as revealed by the analysis.
Keywords: Formal models, GOMS, "Glass-cockpit", Air crew training
A Validation of the GOMS Model Methodology in the Development of a Specialized, Commercial Software Application BIBAKPDF 225
  Richard Gong; David Kieras
A formal GOMS model approach was applied to the design and evaluation of the user interface for a specialized, commercial software application. This approach was able to identify significant usability problems embedded in the procedures by which users interact with the interface. A redesign of the interface based on the GOMS approach resulted in a 46% reduction in learning time and a 39% reduction in execution time during a formal evaluation, differences predicted by the GOMS analysis. Corrections to the GOMS time estimation techniques were necessary to obtain accurate (within 9%) predictions of absolute learning and execution times.
Keywords: GOMS, Analytical methods, Interface design, Usability, User testing, Performance prediction

PAPER ABSTRACTS: Visual Interaction Techniques

A Taxonomy of See-Through Tools BIBAKPDF 225
  Eric A. Bier; Maureen C. Stone; Ken Fishkin; William Buxton; Thomas Baudel
The see-through interface is a new interaction paradigm, based on a set of semi-transparent tools that are moved over an application with one hand while the other applies the tools using a traditional cursor. Compared to traditional interactors, these tools save steps, require no permanent screen space, eliminate temporal modes, allow the user to stay focused on the work area, and are easily customized. This paper presents a taxonomy of see-through tools that considers variations in each of the steps they perform. Our taxonomy is illustrated with example tools that perform graphical editing and text editing operations.
Keywords: User interface, Control panel, Transparent, Multi-hand, Viewing filter, Button, Lens, Menu, Macro
The Alphaslider: A Compact and Rapid Selector BIBAKPDF 226
  Christopher Ahlberg; Ben Shneiderman
Research has suggested that rapid, serial, visual presentation of text (RSVP) may be an effective way to scan and search through lists of text strings in search of words, names, etc. The Alphaslider widget employees RSVP as a method for rapidly scanning and searching lists or menus in a graphical user interface environment. The Alphaslider only uses an area less than 7 x 2.5cm2. An experiment was conducted with four Alphaslider designs which showed that novice Alphaslider users could locate one item in a list of 10,000 film titles in 24 seconds on average.
Keywords: Alphaslider, Widget, Selection technology, Menus, Dynamic queries

PAPER ABSTRACTS: Designing Interaction Objects

Specification of Interface Interaction Objects BIBAKPDF 226
  David A. Carr
User Interface Management Systems have significantly reduced the effort required to build a user interface. However, current systems assume a set of standard "widgets" and make no provisions for defining new ones. This forces user interface designers to either do without or laboriously build new widgets with code. The Interface Object Graph is presented as a method for specifying and communicating the design of interaction objects or widgets. Two sample specifications are presented, one for a secure switch and the other for a two dimensional graphical browser.
Keywords: User interface specification, User interface design
Recursive Interfaces for Reactive Objects BIBAKPDF 227
  Michael Travers
LiveWorld is a graphical environment for programming with reactive objects. It offers novice users a world in which graphic objects and program elements are integrated into a single interaction framework. To manage the diversity of object types in LiveWorld, it uses an unusual object system in which the separate categories of classes, objects, and slots are replaced with a single type of entity, the frame, that has a simple and intuitive graphic representation. This unification enables the construction of an integrated interface that achieves elegance, simplicity and power, and can provide conceptual scaffolding for novices to enter into programming.
Keywords: Programming environments, Objects, Direct manipulation, Visual object-oriented programming, Agents, Rules

PAPER ABSTRACTS: HCI in the Real World

The Value of a Baseline in Determining Design Success BIBAKPDF 227
  Brenda Burkhart; Darold Hemphill; Scott Jones
This paper examines the value of a baseline for usability testing in a software development organization and the specific issues that arose during the implementations of the usability test. Specifically, this testing involved the transitioning of a character-based user interface to a graphical user interface. In order to assess the efficacy of the new design and to determine if performance improvements were achieved with the new interface, a baseline was established to enable a comparative usability assessment. This usability test focused on comparing performance on similar tasks for both interfaces. Results indicated that the new interface was faster than the old interface for similar tasks. Usability goals were established at an arbitrary 50% improvement in task time over the old system. An average of 56% improvement was achieved. Advantages of the comparative design, namely better identification of tasks to target for improvement and establishment of an archive of data, are discussed. In addition, recommendations for reducing the effort involved in staging a comparative usability test are discussed.
Keywords: Comparative testing, Baseline, CUI, Design principles, GUI, Usability testing, Usability goals
User Preferences for Task-Specific vs. Generic Application Software BIBAKPDF 228
  Bonnie A. Nardi; Jeff A. Johnson
We conducted an ethnographic study to investigate the use of generic vs. task-specific application software by people who create and maintain presentation slides. The study was motivated by our beliefs that: 1) some software programs are task-generic, intended for use in a wide variety of tasks, while others are task-specific, intended to support very specific tasks; 2) task-specific software is preferable, but is often not used because of cost, learning effort, or lack of availability; and 3) people who infrequently perform a task tend to use generic tools, while people who frequently perform a task tend to use task-specific tools. Our findings suggest that the truth is more complex.
Keywords: Task-specificity, Task analysis, Slidemaking, End user computing, Interoperability, Collaborative work
Surrogate Users: Mediating Between Social and Technical Interaction BIBAKPDF 228
  Deborah Lawrence; Michael E. Atwood; Shelly Dews
Although human machine interaction is typically studied in the context of one person interacting with a computer, people often interact with computers in support of their communication with other people. Telephone operators are an excellent example of such "surrogate users"; they use workstations to carry out a goal for a customer, such as finding a telephone number. As the customer's intermediary, the operator must construct an accurate and well-specified search, though the information offered may be incomplete or inaccurate. We have examined both the social interaction and the human-computer interaction in such situations using several different types of analysis, first in CPM-GOMS models and more recently in dialogue analysis and analysis of dialogue timelines. Our work has alerted us to the special human performance requirements of surrogate user tasks.
Keywords: Dialogue analysis, System evaluation, Surrogate users, Database retrieval

PAPER ABSTRACTS: Evaluating Pointing Devices

Children's Use of Mouse-Based Interfaces to Control Virtual Travel BIBAKPDF 229
  Erik Strommen
Children's performances using three different mouse interfaces to control point-of-view (POV) navigation in a prototype of a CD-ROM based "virtual forest" were assessed. Results indicate that while children readily understood POV movement and were able to use all three interfaces successfully, each interface was less than optimal for different reasons. An assessment of the strengths and weaknesses of each interface in light of the intended usage scenario was conducted, and the least problematic of the three was selected for the system.
Keywords: Children, Interface, Virtual travel
The Effect of Reducing Homing Time on the Speed of a Finger-Controlled Isometric Pointing Device BIBAKPDF 229
  Anant Kartik Mithal; Sarah A. Douglas
This paper examines a new pointing device. Subjects' pointing performance was compared in two tasks. One task required pointing, the other pointing and typing. One group used a keyboard and mouse. The other used a keyboard with integrated joystick under the "J" key. The mouse was faster despite the reduction in homing time shown by the joystick and keyboard combination. We show that the mouse is the faster pointing device; that a finger controlled device complies with Fitts' law; and that for designing faster pointing devices, increasing the Fitts' Law Index of Performance is more important than reducing homing time.
Keywords: Fitts' law, Pointing devices, Homing time, Keystroke level model, Index of difficulty, Index of performance, Mouse, Joystick
Two-Handed Input in a Compound Task BIBAKPDF 230
  Paul Kabbash; William Buxton; Abigail Sellen
Four techniques for performing a compound drawing/color selection task were studied: one unimanual, one bimanual where different hands controlled independent subtasks, and two bimanual, where the action of the right hand depended on that of the left. We call these latter two "asymmetric dependent." Since they closely conform to everyday bimanual tasks, we predict they would give rise to the best performance. One, called Toolglass, did. The reasons and implications for design are discussed. These are contrasted with other kinds of two-handed techniques, and it is shown below how, if designed inappropriately, two hands can be worse than one.
Keywords: Two-handed input, GUIs, Toolglass, Palette menus, Compound tasks

PAPER ABSTRACTS: Analysis of Programming Environments

In Search of Design Principles for Programming Environments BIBAKPDF 230
  Stephanie Houde; Royston Sellman
Software development environments are becoming progressively more advanced in their support for construction of large software applications. However, it is still tedious and time consuming for programmers to build even simple applications. This paper describes an exploratory study which identifies some common problems experienced by programmers working with a range of currently available tools. Eight professional programmers were observed while each built the same simple application using a different software development environment. Problems encountered during the authoring process were noted. Four categories of common problems emerged. Design principles implied by these categories are suggested.
Keywords: Programming environments, Authoring tools, User-centered design
Programmable Design Environments: Integrating End-User Programming with Domain-Oriented Assistance BIBAKPDF 231
  Michael Eisenberg; Gerhard Fischer
Programmable design environments (PDEs) are computational environments that integrate the conceptual frameworks and components of (a) design environments and (b) programmable applications. The integration of these two approaches provides elements (such as software "critics" and "queryable objects") that assist users in learning both the application and its domain; in addition, an interactive "application-enriched" end-user programming environment stresses the values of expressiveness and modifiability. By way of illustration, we present a newly-developed programmable design environment, SchemeChart, for the domain of charting and information displays.
Keywords: Programmable design environments, End-user programming, Programmable applications, Domain-oriented design environments, Critics

PAPER ABSTRACTS: Cognitive Models

"Why is a Raven Like a Writing Desk?" Lessons in Interface Consistency and Analogical Reasoning from Two Cognitive Architectures BIBAKPDF 231
  John Rieman; Clayton Lewis; Richard M. Young; Peter G. Polson
Users who have worked with just a few pieces of application software on a computer system are often faced with the need to use a new program on the same system. Consistency between program interfaces is intended to make new software easier to learn, but how "consistency" should be defined is not clear. We present a model of analogical reasoning that describes how users rely on interface consistency to induce correct actions in a new situation. Versions of the model are implemented in ACT-R and Soar. The model yields a more principled understanding of design guidelines that recommend consistency.
Keywords: User models, Consistency, Exploratory learning, Analogy, Metaphor
A Model of the Acquisition of Menu Knowledge by Exploration BIBAKPDF 232
  Andrew Howes
This paper reports a mechanism that learns how to use a menu structure by exploration. The model, called Ayn, starts without any knowledge of the menus but when given a goal, explores and tries out options until the goal has been achieved. During this process it constructs a long-term, recognition-oriented, memory of its behavior so that on future occasions it will be able to achieve the same goal without exploration. The mechanism captures three aspects of human behavior: it learns while interacting with the device, it speeds up with practice, and it acquires display-based knowledge.
Keywords: Exploratory learning, Cognitive models, Working memory, Practice, Menus, Display-based knowledge

PAPER ABSTRACTS: Interacting in 3-D

Passive Real-World Interface Props for Neurosurgical Visualization BIBAKPDF 232
  Ken Hinckley; Randy Pausch; John C. Goble; Neal F. Kassell
We claim that physical manipulation of familiar real-world objects in the user's real environment is an important technique for the design of three-dimensional user interfaces. These real-world passive interface props are manipulated by the user with both hands to specify spatial relationships between interface objects. We present neurosurgical planning as a driving application and demonstrate the utility of a head prop, a cutting plane prop, and a trajectory selection prop in this domain. Our informal evaluations have shown that with a cursory introduction, neurosurgeons who have never seen the interface can understand and use it without training.
Keywords: Three-dimensional interaction, Gesture input, Two-handed interaction, Haptic input, Neurosurgery, Visualization
The "Silk Cursor": Investigating Transparency for 3D Target Acquisition BIBAKPDF 233
  Shumin Zhai; William Buxton; Paul Milgram
This study investigates dynamic 3D target acquisition. The focus is on the relative effect of specific perceptual cues. A novel technique is introduced and we report on an experiment that evaluates its effectiveness. There are two aspects to the new technique. First, in contrast to normal practice, the tracking symbol is a volume rather than a point. Second, the surface of this volume is semi-transparent, thereby affording occlusion cues during target acquisition.
   The experiment shows that the volume/occlusion cures were effective in both monocular and stereographic conditions. For some tasks where stereographic presentation is unavailable or infeasible, the new technique offers an effective alternative.
Keywords: 3D interface, Interaction technique, Target acquisition, Virtual reality, Fitts' law, Input, Depth perception
Direct and Intuitive Input Device for 3-D Shape Deformation BIBAKPDF 233
  Tamotsu Murakami; Naomasa Nakajima
Standard input devices such as a mouse and a keyboard in present computer-aided design systems do not provide users with direct and intuitive facilities for highly 3-D shape manipulation. To solve the problem, this paper proposes a new interface system for 3-D shape manipulation by adopting a real elastic object as an input device. By deforming the device with bare hands with a tactile feedback, users can manipulate a 3-D shape modeled and displayed on a computer screen quite directly and intuitively. A prototype with a cubical input device made of electrically conductive polyurethane foam is also presented.
Keywords: Human interface, Computer graphics, Input device, Computer-aided design, Free-form deformation