Manfred Thüring

Hypermedia and cognition: designing for comprehension

hypermedia, it is necessary to distinguish between two kinds of applications: “One encourages those who wish to wander through large clouds of information, gathering knowledge along the way. The other is more directly tied to specific problem-solving, and is quite structured and perhaps even constrained” [20, p. 119]. Applications of the first type appear as browsable databases—or hyperbases—that can be freely explored by a reader. In contrast, applications of the second type take the shape of electronic documents—or hyperdocuments—that intentionally guide readers through an information space, controlling their exploration along the lines of a predefined structure. Each type has its particular advantages and encourages different reading strategies. While the first one is better suited to support unconstrained search and information retrieval, the second one is more adequate for tasks requiring deep understanding and learning. As Hammond points out, it “may be fun and perhaps instructive, to open every door and peer inside, but there are many situations where learning is most effective when the freedom of the learner is restricted to a relevant and helpful subset of activities.” It is this second type of task—reading a hyperdocument for learning—that we address in our discussion of “designing for comprehension.”

SEPIA: a cooperative hypermedia authoring environment

This paper addresses two main areas: 1) research on computer–based support for cooperative authoring and 2) research on cooperative hypermedia systems. This is done by reporting about the design, development, and implementation of SEPIA and presenting results on dedicated and comprehensive authoring functionality addressing also the new rhetoric of hypermedia, a hypermedia data model with composites, persistent and shared data storage for hypermedia, and support for cooperative work, esp. cooperative writing.We start by identifying the challenge of hypermedia authoring and production which serves as the driving force for our development. Using interacting problem spaces as the vehicle for modelling the dynamic aspects of authoring, we arrive at a set of requirements answered by the concept of “activity spaces”. The design of coherent hyperdocuments is facilitated by a “construction kit”. Furthermore, we describe the extensions and modifications necessary to support multiple authors with the cooperative version of SEPIA. Based on the requirements, we develop a system architecture and report on the implementation of the system. We describe the basis for access to shared hyperdocuments, the activity space browsers, the integration of multimedia functionality (audio, graphics, pictures), and the integration of an audio and video conferencing system. Finally, we report on more recent developments and future work.

From ideas and arguments to hyperdocuments: travelling through activity spaces

Discussing relevant issues for the next generation of hypermedia systems, Halasz [Hala88] provides also a classification along the following three dimensions: scope, browsing vs. authoring, and target task domain. In this paper, we will especially discuss aspects of the second dimension focussing on support for idea processing and authoring in hypertext systems. Although one cannot classify existing systems by assigning them exclusively to one category of this dimension1 hypertext systems are primarily discussed from the reading and browsing point of view and as support for retrieval. This is also reflected in attempts to transform existing (linear) text sources into hypertext structures in order to pro& from their additional interactive branching capabilities.

What's Eliza doing in the Chinese room? Incoherent hyperdocuments—and how to avoid them

A signal consisting of square pulses is applied to an FSK transmitter and is transformed into a control signal consisting of substantially symmetrical trapezoidal pulses. This control signal is applied on the one hand to a gyrator oscillator modulator to generate an FSK signal and on the other hand to a conversion device which converts the control signal into a direct voltage signal the direct voltage value of which shows a positive pulsatory variation each time during the occurrence of the edges of the trapezoidal pulses of the control signal. Said direct voltage signal is used to subsequently modulate the FSK signal in an amplitude modulator. The amplitude-modulator FSK signal may now be applied directly as a modulation signal to a carrier modulator without the intermediary of a band-pass filter.

Ein Ansatz zur Organisation von Hyperdokumenten

In diesem Beitrag wird ein Ansatz zur Strukturierung von Hyperdokumenten vorgestellt. Die Forschung zum Textverstehen hat gezeigt, das sowohl die Orientierung in einem linearen Text als auch dessen Verstandnis entscheidend durch Gestaltungsmittel beinflust wird, die es Lesern erlauben, eine koharente mentale Reprasentation des Textinhalts aufzubauen. Zu Beginn dieses Beitrags werden daher die Koharenzmerkmale linearer Texte diskutiert und auf Hyperdokumente ubertragen. Anschliesend werden vor dem Hintergrund eines Designkonzeptes Strukturierangs- mittel fur die Produktion von Hypertexten beschrieben, die ein Autor einsetzen kann, um die Koharenzbildung seiner Leser zu fordern. Dabei wird von drei funktionell verschiedenen Komponenten eines Hyperdokumentes ausgegangen, die wir als Inhalts-, Organisations- und Prasentationskomponente bezeichnen. Abschliesend werden die vorgestellten Strukturierungskonzepte anhand eines Beispieldokuments illustriert.

Hyperdocuments as user interfaces: Exploring a browsing semantic for coherent hyperdocuments

For moving hypertext out of the labs into a wide-spread use, it is crucial to improve the quality of its on-line presentation. To reach this goal, it is not sufficient to concentrate on navigation and neglect support for better comprehension. Improving the understanding of a hyperdocument can be accomplished by imposing a coherent structure on the document and by conveying it to the reader. In this paper, we describe an approach which follows this idea: Based on a construction kit for coherent hyperdocuments, we have developed a user interface which combines the presentation of structure and content with additional orientation cues and facilities for comfortable navigation. Using a prototypical hyperdocument as an example, this browsing semantic is explained and its impact on comprehension and navigation is dicussed.

What Matters in Developing Interfaces for Hyperdocument Presentation

For the last few years, interface design in the domain of hypertext has mainly focused on the solution of the navigation problem. Moreover, browsing has been regarded as the most central user activity. While this claim may hold for hypertexts that do not demand a reader’s full attention, such as information kiosks or electronic advertisements, its validity must definitely be doubted for the majority of hyperdocuments. “Reading ... hypertext about matters that deeply matter to us” (Bernstein, 1991b, p.365) requires a lot more concentration and mental effort than careless node hopping. Therefore, navigation should not be regarded as an end in itself but as a mere precondition for the reader’s actual goal: the comprehension of the hyperdocument. Interface design focusing on this neglected issue may help to avoid what Foss (1989) has termed the “Art Museum Phenomenon” of hypertext, i.e., that “after you have spent a long day in a large art museum gazing a hundreds of paintings ... at the end of the day you may not be able to tell someone what you have seen” (p. 408). To overcome this phenomenon interfaces are required which significantly increase the readability of hyperdocuments.

Architecture and User Interface of the IDEAS Intelligent Documentation System

In pharmaceutical industry, each new drug is tested in clinical studies before it is released on the market. Any adverse event occurring in such a study requires a difficult decision: Is the event caused by the drug under investigation or by other factors? The human decision maker trying to answer this question faces a complex problem and must consider a multitude of heterogeneous data and numerous knowledge sources. IDEAS is an intelligent documentation system (IDS) that supports this type of complex decision making. It provides (a) a model of expertise from which all relevant data and knowledge sources can be easily accessed and (b) an action event model which documents the results of the decision process. The IDEAS system is designed as a hypertext application implemented in a spreadsheet environment. The combination of the model of expertise with the’ spreadsheet Metaphor’ aims to overcome well-known problems of hypertexts, such as ‘disorientation’, ‘cognitive overload’ and ‘overchoice’.

Hypermedia Applications for Distance Education and Training

Almost all sectors of modern society have to cope with a rapidly growing amount of information. The knowledge required from persons living and working in such a society is continuously expanding and gets more complex everyday. Education is no longer the exclusive business of schools and universities but has also become a matter of concern for enterprises training their employees. In order to provide products and services of high quality, companies must ensure that their personnel is – and remains – highly qualified. This situation has not only caused a considerable increase of public and private investments in education within recent years (Zimmer, 1990), it has also transformed learning from a process delimited to an individual’s youth into a life-long activity that accompanies work and employment. It is this very feature of learning that serves as a catalyst increasing well known issues in education and training: ♦ The spatial distribution and time constraints of learners lead to difficulties in coordination and integration of training into everyday work. ♦ Innovation cycles of information are sometimes faster than education and training programs for conveying this information to a larger group, i.e., a course may be outdated even before each participant has accomplished it. ♦ The potentials of multimedia materials are not yet fully exploited for today’s teaching nor are they optimally integrated into facilities for education and training. ♦ Inadequate or missing tailoring of information to the background and knowledge of the individual learner reduce the efficiency of courses.

Hypertext Application Design using a Model-Based Approach

In this paper, the first results of the ESPRIT project HYTEA (HYperTExt Authoring) will be presented. HYTEA aims at supporting the construction of large and complex hypertext/hypermedia (“HT/HM”) applications. For this purpose, the Hypertext Design Model (HDM) is introduced which serves as a high-level data structure for hyperdocument design. Within HYTEA, a variety of prototype applications are specified and implemented that use HDM as a modelling device. In order to exemplify this approach, we will describe one application in detail: the design of a hypertext online documentation for a user manual of the forms processing system SIFORM. Another objective of HYTEA is the development of tools which are conceptually based on HDM and provide a graphical interface for easy and efficient hyperdocument authoring. Two of these tools will be presented in order to illustrate the HYTEA approach for the design and maintenance of HT/HM applications.