Paul Kahn

Pushing reuse in hypermedia design: golden rules, design patterns and constructive templates

Reuse is increasingly strategic for reducing cost and improving quality of hypermedia design and development. In this paper, based on the design and development of a real hypermedia application, we classify and explore different types of reuse in hypermedia design. We show how constructive templates constitute a practical technique for capturing the specification of reusable structures and components and enabling the automation of the production process. We also discuss connections between constructive templates and design patterns.

MAPA: a system for inducing and visualizing hierarchy in Websites

The MAPA system provides improved navigation facilities for large web sites. It extracts a hierarchical structure from an arbitrary web site, with no or minimal human assistance, and creates an interactive map of that site that can be used for orientation and navigation. MAPA is designed and most useful for large web sites of from 500 to 50,000 pages. We present an overview of the mapping problem, with a list of 10 important user facilities that maps can offer. Then we describe how the MAPA system analyzes the link structure of a site, and provides effective aids for the navigation of large hypertexts. We also compare MAPA with a number of other web-mapping systems, and conclude with a review of how MAPA stands with respect to our wish-list of map features.

Visual cues for local and global coherence in the WWW

The user of a hypermedia publication needs to be supported in two interrelated tasks: local and global navigation. Local navigation involves following hypertext connections between pairs of specific nodes. Global navigation involves movements within a collection of information that spans many nodes. Local and global navigation are directly related to the underlying concepts of local and global coherence, as defined in the article by Thuring et al. in this issue. To maintain a user’s sense of orientation and facilitate navigation, the designer of a hypermedia publication must support both at the visual level. The World-Wide Web (WWW), while providing a simple and effective form of creating and displaying links between nodes, challenges the author/designer to present any global context at all. There is no way to distinguish between local and global link structures in HTML, the markup language used to create WWW documents. The WWW browser provides three pieces of orientation information: (a) the title of the current document; (b) the Universal Resource Locator (URL) of the current document; and (c) the URL of a link destination. None of

Where's the hypertext: The Dickens Web as a system-independent hypertext

This paper reports the comparative evaluations by fifteen experienced hypertext users of three hypertext systems (Intermedia, Interleaf WorldView, and Storyspace) to carry out both simple information retrieval and more complex cognitive tasks. In contrast to, approaches that compare hypertext versions of print documents to print documents, our research began with materials originally created for an electronic environment—the award-winning Dickens Web. The evaluators’ detailed narratives, which show that hypertext documents can exist independently of specific hypertext systems, also suggest points that designers of hypertext systems and hypertext authors must take into account. These points include the value of fulltext search vs. link following, and the importance of content expertise. Finally, we report on the importance of singlevs. hi-directional thinking, multiple linking from a single point, and web views.

The pleasures of possibility: what is disorientation in hypertext?

THIS PAPER reports the comparative evaluations by fifteen experienced hypertext users of three hypertext systems (Intermedia, Interleaf Worldview, and Storyspace). The evaluators’ detailed narratives suggest points that designers of hypertext systems and hypertext authors must take into account, including the importance of content expertise, personal or idiosyncratic approaches to reading hypertexts, the ineffectiveness of page metaphors, and crucial differences between the way experienced and novice users view disorientation. The evaluators’ reactions also suggest that the matter of disorientation in hypertext is an inadequately considered phenomenon.

Three Fundamental Elements of Visual Rhetoric in Hypertext

The design of information on the printed page or on the computer screen must express the overall structure of that information in order to be understood by the reader. Various conventions of typography communicate the meta-structure of a block of text such as size of type, weight of font, use of indents, initial capitals (derived from illuminated capitals in the manuscript tradition), use of bold and italic variations, and use of color. Analogous conventions exist in information graphics for communicating quantitative information, visual narrative such as instructions, and location graphics such as maps.

Information architecture: a new discipline for organizing hypertext

Hypertext has always been about allowing us to connect information in creative and useful ways. Anything can be linked to anything. This is the promise and problem of hypertext. It is possible to link things well but far easier to link things badly. The result is spaghetti writing to go with our spaghetti code, masses of senseless trails and tunnels where the reader loses all sense of attention and purpose. The computer science community responded to this diet of pasta with new practices, promoting interoperable, repeatable, reusable, object-oriented programming tools.

The Educational Uses of Intermedia

THIS ESSAY discusses the use of Intermedia as an educational tool. After briefly describing the kinds of educational problems the software was intended to address, we shall survey some of the materials created using Intermedia and compare how the tools have been used in a variety of educational contexts. Based on this survey and our own experience as Intermedia authors and editors, we will offer some conclusions concerning the effectiveness of the Intermedia tools themselves. An annotated bibliography lists relevant IRIS technical papers and publications by Intermedia users.

From Memex to hypertext: understanding the influence of Vannevar Bush

The history of hypertext is often traced back to the description of Memex in “As We May Think by Vannevar Bush. Despite its common use in citations, Bush’s work is not well understood by the hypertext community. The moderator and James M. Nyce have edited From Memex to Hypertext: Vannevar Bush and the Mind’s Machine (1991, Academic Press), collecting all of Bush’s writings on Memex. The book features critical essays on Bush and his influence on today’s hypertext software by members of the panel.