This paper examines open hypermedia systems, and presents the case that such systems provide a step forward for dealing with large, dynamic data sets in distributed, heterogeneous environments by allowing users to access and integrate information and processes in richer and more diverse ways than has previously been possible. In particular, the enhanced Microcosm model for open hypermedia is examined, and the ways in which it provides such an environment are discussed. The paper continues by investigating the advantages and the shortcomings of this model and identifies the areas in which further work must be completed before such systems can become widely adopted, such as the granularity of source and destination anchors, editing and version control. Some attempts to provide solutions to these problems are presented and discussed.

There are currently a number of commercially available hypertext and hypermedia systems, of varying levels of sophistication and usability, but there are still many problems to be resolved in the design of such systems. In this paper, we itemise some of the major problems that we have identified as possibly causing a barrier to the growth and development of hypermedia applications outside the research community. A model of an open hypermedia architecture with dynamic linking features is proposed that moves some way to resolving these problems, and the first implementation of the system, Microcosm, is presented and discussed.

: ET++ is a homogeneous object-oriented class library integrating user interface building blocks, basic data structures, and support for object input/output with high level application framework components. The main goals in designing ET++ have been the desire to substantially ease the building of highly interactive applications with consistent user interfaces following the well known desktop metaphor, and to combine all ET++ classes into a seamless system structure. Experience has proven that writing a complex application based on ET++ can result in a reduction in source code size of 80% and more compared to the same software written on top of a conventional graphic toolbox. ET++ is implemented in C++ and runs under UNIX^TM and either SunWindows^TM, NeWS^TM, or the X11 window system. This paper discusses the design and implementation of ET++. It also reports key experience from working with C++ and ET++. A description of code browsing and object inspection tools for ET++ is included a...

The concept of a path, or ordered traversal of some links in a hypertext, has been a part of the hypertext notion from its early formation. Although paths can help to solve two major problems with hypertext systems, namely user disorientation and high cognitive overhead for users, their value has not been recognized. Paths can also provide the backbone for computations over a hypertext, an important issue for the future of hypertext. This paper constructs a framework for understanding path mechanisms for hypertext and explores the basic issues surrounding them. Given this framework, it reviews path mechanisms that have been provided by other hypertext systems. Finally, it describes the Scripted Documents system, which has been developed to test the potential of one powerful path mechanism. 1. Introduction Hypertext is a valuable contribution to the information age, allowing readers to access related information through machine-supported links. However, current hypertext systems have se...

In this paper we discuss the architecture and implementation of CMIFed, an editing and presentation environment for hypermedia documents. Typically such documents contain a mixture of text, images, audio, and video (and possibly other media), augmented with user interaction. CMIFed allows the author flexibility in specifying what is presented when, using multiple simultaneous output channels. Unlike systems that use a timeline or scripting metaphor to control the presentation, in CMIFed the user manipulates a collection of events and timing constraints among those events. Common timing requirements can be specified by grouping events together in a tree whose nodes indicate sequential and parallel composition. More specific timing constraints between events can be added in the form of synchronization arcs. User interaction is supported in the form of hyperlinks. We place CMIFed in the context of the Amsterdam model for hypermedia documents, which formalizes the properties of hypermedia ...

It has been shown that the famous problem of user disorientation in hypertext is not due to the concept of hypertext itself but rather generally results from the lack of a conceptual model for hypertext application. Unfortunately, in most hypertext systems, the weakness of structure specification mechanisms discourages the development and use of such a model since it is difficult to reinforce hypertext structure and to really incorporate knowledge. A lot of works provide intelligent mechanisms to help navigation but either they use external knowledge or automatically synthesize links from information included in nodes which thereby have no sufficient conceptual value. The present paper focuses on an object-oriented hypertext model (implemented in the MacWeb system) using structured types to incorporate knowledge in hypertext. Concepts and their relationships as well as their instances and their own relationships may be represented. Such a model makes the capture of knowledge at source easier thus allowing a more conceptual navigation, Furthermore, active behaviors may be associated, as methods, to types. This provides a powerful mechanism to help develop structured hypertext as well as task centered applications, by taking advantage of knowledge representation.

this paper, we give a vision of third- and fourth-generation hypermedia, and some direction for developers to implement them on the web---and indeed in other information systems

Hypermedia is often viewed as either a paradigm for human-computer interaction or information organization. Human-computer interaction provides a view of hypermedia that involves the creation, manipulation, and access of information through a "point-and-click" navigation mechanism. Information organization provides a view of hypermedia that involves the storage of information as a set of data and metadata objects, where metadata objects capture structural relationships among information objects. This paper describes a third view of hypermedia --- hypermedia as a computing paradigm. In this paper, we explore the implications of pushing hypermedia beyond its traditional role in human-computer interaction and information organization into the computer's core operating environment. We believe the resulting hypermedia operating systems provide a new paradigm for computing --- one in which human-computer interaction, information storage and retrieval, programming, and control are integrated ...

this article we describe how developers can incorporate hypertext functionality into computational applications. What benefit do users gain from hypertext support in computational applications? Managing the myriad of interrelationships in a computational application's knowledge (data and calculated information) is difficult for a user. It can be improved by streamlining access and increasing user comprehension through interface enhancements (e.g., visualization). Augmenting an application with hypertext support results in new ways to view and manage the application's knowledge, by navigating among items of interest and annotating with comments and relationships (links). Unfortunately, many computational system developers view hypertext only in terms of accessing and managing documents (or smaller units of static information) . Such display-oriented behavior characterizes the majority of hypertext systems. SEPIA (see Thring et al. and Streitz in this issue), KMS [1], Aquanet and VIKI

In this paper, we argue that some tasks (e.g., meeting support) require more flexible hypermedia systems and we describe a prototype hypermedia system, DOLPHIN, that implements more flexibility. As part of the argument, we present a theoretical design space for information structuring systems and locate existing hypertext systems within it. The dimensions of the space highlight a system's internal representation of structure and the user's actions in creating structure. Second, we describe an empirically derived range of activities connected to conducting group meetings, including the pre- and postpreparation phases, and argue that hypertext systems need to be more flexible in order to support this range of activities. Finally, we describe a hypermedia prototype, DOLPHIN, which implements this kind of flexible support for meetings. DOLPHIN supports different degrees of formality (e.g., handwriting and sketches as well as typed nodes and links are supported), coexistence of different structures (e.g., handwriting and nodes can exist on the same page) and mutual transformations between them (e.g., handwriting can be turned into nodes and vice versa).