Browsing by Author "Witten, Ian"

Now showing 1 - 7 of 7
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    COMPARISON OF MENU DISPLAYS FOR ORDERED LISTS
    (1985-09-01) Greenberg, Saul; Witten, Ian
    Menu selection is a popular way of accessing databases and command sets. When the database can be categorized on a semantic basis, each menu entry usually reflects a "field of knowledge". However, some information - such as the ordered sequential lists found in telephone directories - cannot be easily categorized, and must use a presentation scheme which divides entries into ranges using lexical ordering. This paper reports a human factors investigation of six possible menu displays for alphabetically-ordered lists. It offers clear guidance as to which menu format provides the best human performance in terms of scanning speed and error rate. Novice and expert computer users are also compared, with results indicating that novices have slower scanning speeds and greater sensitivity to menu displays than experts. Differences between human performance in scanning root menus and menus buried deep in hierarchies are also studied. The results suggest that the traversal of alphabetic menu hierarchies should avoid, as much as possible, descending deep into the tree, for user efficiency deteriorates with depth.
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    HOW TO GET A RESEARCH GRANT
    (1990-04-01) Witten, Ian
    No Abstract
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    ISSUES AND EXPERIENCES IN THE DESIGN OF A WINDOW MANAGEMENT SYSTEM
    (1986-09-01) Greenberg, Saul; Peterson, Murray; Witten, Ian
    Window systems underlie many successful human-computer interfaces. But constructing them involves several fundamental design issues which are resolved in various ways by different implementations. These affect both user's and programmer's interface, and include tiling vs overlapping windows; program vs user control of windows; techniques for coping with changeable window sizes; design of transient windows; low-level vs high-level tools for the programmer; local vs distributed control; and the role of a controlling window manager process. There is no broad consensus among designers as to how best to make such decisions. This paper illuminates the issues involved by surveying characteristics of window systems and discussing dominant design questions. The philosophy and implementation underlying the JADE window manager constructed at the University of Calgary is revealed, and the design is reevaluated from the perspective of three years' experience of using the system and programming within it.
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    JADE: a simulation & software prototyping environment
    (1983-11-01) Unger, Brian W; Birtwistle, Graham; Cleary, John; Hill, David; Lomow, Greg; Neal, Radford; Peterson, Murray; Witten, Ian; Wyvill, Brian
    Jade provides an integrated set of tools which are designed to support the development of distributed software and systems. The Jade environment provides tools for the design, implementation, debugging, testing, maintenance, and performance analysis of distributed, concurrent programs. Novel features of Jade are that it is based on the modelling and simulation of target distributed systems and partially automatic program generation is supported. The goals of Jade are to provide a cost effective software development environment that is both easy and comfortable to use, and which can produce more reliable, maintainable programs. This paper presents an overview of the Jade environment, describes its major components, and outlines the status of the project.
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    ON THE INCLUSION AND PLACEMENT OF DOCUMENTATION GRAPHICS IN COMPUTER TYPESETTING
    (1981-09-01) Corbett, Chris; Witten, Ian
    Computer typesetting systems can produce high quality printed pages suitable for the production of books, journals, and newspapers in final form. Little effort to date has been applied to the problem of including and placing arbitrary graphic figures within processed text. In this paper we describe a system, constructed around existing typesetting software, which allows figure definition and placement. Key features of the system are a wide range of figure sources; figure preview facilities; figures-only output and compatibility with non-graphic printing devices, where figures are plotted separately; support of a figure language for in-line figure definition; and figure placement algorithms which are changeable at the user level.
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    USER INTERFACES
    (1989-09-01) Greenberg, Saul; Witten, Ian
    No Abstract
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    THE WORM THAT TURNED: A SOCIAL USE OF COMPUTER VIRUSES
    (1989-07-01) Witten, Ian; Thimbleby, Harold
    No Abstract