A User-Configurable Hypermedia-Based Interface Via the Functional Model of the Link

Hypermedia management systems often make use of database management systems for the persistent storage of links and of the linked information components. In this paper, we argue that a hypermedia management system with its support for reader-directed navigation provides an attractive type of database system interface in that it facilitates ease of database access or more specifically, of locating (‘discovering’) relevant information.

Furthermore, our approach to hypermedia management, based on the Functional Model of the link, provides for extensive user-configurability of that interface. This configurability particularly applies to fully dynamic links, which free the user from much of the link creation and maintenance duties.

A prototype system incorporating this approach is overviewed in this paper.     

The hype and the media: Issues concerned with designing hypermedia

Many claims and much 'hype' surround the term 'hypermedia'. Foremost amongst these claims are that hypermedia will revolutionize learning and users' abilities to interact with, search for, and tailor information to suit their own needs. These claims are similar to those made about 'hypertext' in the past. Our point of view is that hypermedia is 'more than just the sum (i.e. the overall effect) of the parts' (e.g. sound, video, graphics, text etc.). In this paper we offer definitions for the terms 'multimedia' and 'hypermedia' and examine some of the above claims using examples from a collaborative research and development project at the Open University and Rank Xerox EuroPARC. We consider what basic psychological principles can tell us about designing hypermedia from a usability perspective, apply these ideas to specific design issues, and raise some development issues which have also influenced our design of hypermedia. We conclude that further research and creative exploration are needed to understand how best to harness the potential of combining multiple media into well designed hypermedia systems.     

Open and Reconfigurable Hypermedia Systems: A Filter-Based Model

The need for open hypermedia systems has been well-argued by various authors. In this paper we discuss the Microcosm model for open hypermedia and show how filters have been used to extend this model both for greater efficiency and to make it totally reconfigurable. This enables users to tailor the functionality of the system to meet their own requirements, for example to select different sets of links, or to add navigation tools. The implementation of a management system for filters is described, and examples of how it has been used to extend the functionality of the model are presented, in particular the use of filters to design and implement a set of navigation tools for Microcosm. This latter case study demonstrates the power and flexibility of the filter-based model since all navigation tools for the system can be implemented as filters. The filter technology is discussed in the context of Microcosm but can be generalised to other hypermedia systems.     

Automating Hypermedia for Decision Support

Many ‘first generation’ hypermedia systems were designed to support applications, which do not require the dynamic and general characteristics necessary for our domain --- decision support systems (DSS). The heart of our research is a dynamic model of hypermedia incorporating virtual structures and computation, which we call generalized hypermedia. Generalized hypermedia broadens and automates the ‘static’ or non-virtual notion of first generation hypermedia for a knowledge-based DSS shell. The shell provides a hypermedia-style interface for navigating among DSS application models, data and reports. Such a shell should support applications in a variety of fields, e.g., engineering, manufacturing, finance, and therefore must provide hypermedia support as general, system-level functionality Generalized hypermedia superimposes a hypermedia network on a DSS application, generating all hypermedia nodes, links and link markers dynamically from the application's standard, non-hypermedia knowledge base. In this paper we demonstrate how automating hypermedia can enhance decision making with a DSS. We describe generalized hypermedia and discuss the challenges presented to it by a dynamic, real-time environment.     

Extensibility in component-based open hypermedia systems

Extensibility has long been recognized as a highly desirable trait of hypermedia systems. Furthermore, many hypermedia systems claim to provide some form of extensibility. However, consensus on what functionality of a hypermedia should be extensible, how this extensibility should be presented to extension implementers, and even a rigorous definition of the term itself have evaded the hypermedia field. In this paper, we start by offering one possible definition of extensibility. Then, we describe the extensibility mechanisms provided in the HOSS hypermedia system, and analyse these mechanisms in light of our proposed definition. We point out some of the aspects of the design and implementation of the HOSS extensibility mechanism that caused problems for extension developers. We then consider the extensibility mechanisms of Construct, the codebase successor to HOSS and a number of other hypermedia systems, focusing on how the analysis of the HOSS mechanisms affected analogous mechanisms in Construct. We conclude with a reflection upon our proposed definition of extensibility in hypermedia systems.     

Modelling hypermedia and web applications: the Ariadne Development Method

The development process of hypermedia and web systems poses very specific problems that do not appear in other software applications, such as the need for mechanisms to model sophisticated navigational structures, interactive behaviors, interfaces with external applications, security constraints and multimedia compositions. Even though experience, modelling skills and abstractions can be borrowed from existing software design methods, such as object-oriented modelling, hypermedia developers need specific mechanisms to analyze and design using entities that belong to the hypermedia domain (such as nodes, links, anchors and space and time-based relationships). Moreover, hypermedia methods should provide mechanisms to deal with all the aforementioned features in a progressive and integrated way. In this paper, we present the Ariadne Development Method (ADM), a software engineering method that proposes a systematic, flexible, integrative and platform-independent process to specify and evaluate hypermedia and web applications. ADM has been shown particularly useful in complex systems involving a huge number of users with different abilities to access information, with a complex structure where a huge number of nodes have to be organized in a clear way to produce specifications that are discussed by people with an heterogeneous background. This is the case of ARCE, a Latin American project where 21 countries are cooperating to produce a web platform to improve assistance in disaster mitigation situations.     

A hypermedia authoring tool for augmented and virtual reality

Most existing hypermedia authoring systems are intended for use on desktop computers. These systems are typically designed for the creation of 2D documents and therefore employ 2D authoring mechanisms. In contrast, authoring systems for nontraditional multimedia/hypermedia experiences for 3D virtual or augmented worlds focus mainly on creating separate media objects and embedding them within the user's surroundings. As a result, linking these media objects to create 3D hypermedia is a tedious manual task. To address this issue, we present an authoring tool for creating and editing linked 3D hypermedia narratives that are interwoven with a wearable computer user's surrounding environment. Our system is designed for use by authors who are not programmers, and allows them to preview their results on a desktop workstation, as well as with an augmented or virtual reality system.     

The application of transputers to distributed control

This paper describes the development of a flexible control system based on multiple T800 floating point transputers and is presented in two parts. In part 1 of the paper an overview is presented of distributed command and control systems (DCCS) and the suitability of the transputer for implementation within such systems discussed. It is concluded in this initial investigation that the transputer is ideally suited for use in such systems as it is not only a very powerful processing device but the addition of serial communication links allows individual control modules to easily communicate with other controllers, hosts and external devices. In part 2 of the article, entitled 'A parallel architecture for distributed adaptive control', a transputer-based adaptive control module which has been developed is described. The integration of this flexible controller into a distributed control system is also discussed.     

Broadening the Scope of Hypermedia Principles

Hypermedia systems have been implemented for such a wide range of applications that one must wonder whether their principles should not be included among the building blocks of computer environments themselves. In this paper, we argue that this would indeed be desirable and present a model on which such extension could be based.

After a brief review of hypermedia principles and the terminology used in this paper, we give examples of several computer applications in which hypermedia already are or could advantageously be used. We then suggest that most computer applications would greatly benefit if hypermedia were extended from isolated applications to a system-wide facility and that this could substantially simplify implementation of new hypermedia applications. This claim is then generalized and it is shown that extending hypermedia concepts to the organization of the computer environment itself --- the file system --- and to the user interface would make computer environments more flexible and easier to use.

We then list the main characteristics of such a ‘hyperenvironment’ and conclude the paper with an outline of its implementation model and an example.     

Hypermedia systems and other computer support as infrastructure for museums

This paper discusses the feasibility of incorporating modern hypermedia systems in the working structure of museums. In the first part of the paper we discuss the potential for hypermedia in both the public exhibition areas and the backroom infrastructure of museums.The second part of the paper describes a new museum concept, the viewseum, in which objects or processes are not themselves displayed but are ‘virtually’ displayed and manipulated using computers and audio/visual techniques. A viewseum not only provides computerized information, but provides it in a novel form due to new human-machine interfaces. It also adds a strong human-human component due to the fact that a communication system incorporating both annotation and conferencing facilities can be built into the structure. We are in the process of implementing a viewseum in Austria as part of a number of major exhibitions that are currently being planned in that country during the 1990s.     

A hypervideo system generator

In the past, a number of approaches have been proposed for the modeling and implementation of hypermedia and multimedia systems. However, automatic implementation is still lacking with regard to setting up various hypervideo systems. This paper proposes a hypervideo system generator for automatic implementation of various hypervideo systems. The proposed system is established by using a Generalized HyperVideo System (GHVS) model. A HyperVideo Linking Generator (HVLG) is introduced to on-line authoring of a GHVS program for specifying a hypervideo system. A HyperVideo Browser System (HVBS) has been developed for navigating various hypervideo systems. The proposed hypervideo generator has been established on Windows 3.1 and Windows 95, in which several other educational hypervideo applications have been successfully developed. Moreover, with the help of this prototype, the development time to build such hypervideo applications is considerably reduced when compared with the development of the same application using existing programming languages. © 1997 John Wiley & Sons, Ltd.     

Linking Together Books: Experiments in Adapting Published Material into Intermedia Documents

Links are among the distinguishing features of hypermedia and much research revolves around them. We survey issues related to links and address the problem of presenting links in such a way that the user can choose the most appropriate link. This issue is particularly important when a large number of links is available, a subject that has not received much attention yet but will become important as hypermedia document bases grow. We show that presentation of links can be dealt with by filtering out links that are not of interest to the user and by ranking the remaining nodes to simplify choice. After listing several heuristic approaches, we propose a method based on two quantitative measures of knowledge. This method can be used for rigorous numeric ranking of links on the basis of their contribution to the user's total knowledge.     

Hypermedia—introduction and survey

Our paper begins with an introduction to hypermedia presented with the example of a hypothetical hypermedia system. This is followed by an overview of the main hypermedia components visible to the user—data structures, authoring tools, navigation tools, and user interface. In the next section, we present a brief history of hypermedia, list applications in which hypermedia systems have been used, and describe several important commercial products and research projects. The last two sections introduce the major issues facing hypermedia technology and attempt to predict what direction it might take in the near future.     

The development of a sound viewer for an open hypermedia system

Abstract

While rich support for a wide variety of media such as text, video and image is common among contemporary hypermedia systems, so too is the inadequate support for audio. The primary reason that audio has not attracted as much attention as other media can be attributed to its obvious lack of visual identity. The main focus of this work was to identify a generic and meaningful visual representation of audio within a hypermedia context, and significantly promote hypermedia support for audio through the provision of a sound viewer.

This paper describes the inherent difficulties in providing a consistent interface to audio, and discusses in some depth the issues raised during the development process. The sound viewer is then introduced and the associated concepts described. The creation and traversal of links to and from audio are facilitated by the sound viewer across formats including WAV (proprietary digital sound file format from Microsoft), CD (Compact Disc) Audio and MIDI (Musical Instrument Digital Interface). The resultant viewer provides a unified and extensible framework for interacting with audio from within an open hypermedia environment. The open hypermedia system Microcosm was used as the development platform for this work. Microcosm can be augmented to supply a hypermedia link service to additional media with minimal overhead.     

A methodological approach for hypermedia security modeling

In hypermedia systems security is becoming a key requirement to preserve both confidentiality and integrity. Although some authorization models for hypermedia have been proposed, what is needed is to integrate security modeling into the whole development process, so that designers count on methods to specify all the features of their hypermedia systems, including navigation capabilities, interactivity, multimedia features as well as security. In this paper, we describe how security modeling is approached in a methodology for hypermedia systems, called Ariadne, that offers a number of conceptual and platform-independent tools to specify the features of any hyperdocument in an integrated and progressive way.     

Design of adaptive hypermedia learning systems: A cognitive style approach

In the past decade, a number of adaptive hypermedia learning systems have been developed. However, most of these systems tailor presentation content and navigational support solely according to students’ prior knowledge. On the other hand, previous research suggested that cognitive styles significantly affect student learning because they refer to how learners process and organize information. To this end, the study presented in this paper developed an adaptive hypermedia learning system tailored to students’ cognitive styles, with an emphasis on Pask’s Holist–Serialist dimension. How students react to this adaptive hypermedia learning system, including both learning performance and perceptions, was examined in this study. Forty-four undergraduate and postgraduate students participated in the study. The findings indicated that, in general, adapting to cognitive styles improves student learning. The results also showed that the adaptive hypermedia learning system have more effects on students’ perceptions than performance. The implications of these results for the design of adaptive hypermedia learning systems are discussed.     

Methods and techniques of adaptive hypermedia

Adaptive hypermedia is a new direction of research within the area of adaptive and user model-based interfaces. Adaptive hypermedia (AH) systems build a model of the individual user and apply it for adaptation to that user, for example, to adapt the content of a hypermedia page to the user's knowledge and goals, or to suggest the most relevant links to follow. AH systems are used now in several application areas where the hyperspace is reasonably large and where a hypermedia application is expected to be used by individuals with different goals, knowledge and backgrounds. This paper is a review of existing work on adaptive hypermedia. The paper is centered around a set of identified methods and techniques of AH. It introduces several dimensions of classification of AH systems, methods and techniques and describes the most important of them.     

Supporting Hypermedia Services in the User Interface

This paper presents an architecture for developing hypermedia systems in which hypermedia services are provided primarily through the interface and hypermedia components of an application. The architecture relieves the application component and its developers from the issues associated with hypermedia. It also allows a common hypermedia engine and interface to be used in multiple applications to present a consistent view of a hypermedia model. A prototype of the architecture is presented with examples of the hypermedia facilities which can be provided. The discussion associated with the prototype demonstrates that many of the common features of pure hypermedia systems can be supported. Limitations and future research issues also are discussed.     

超媒体计算机教学系统的设计

本文首先分析当前超媒体教学系统的不足,并在此基础上给出超媒体计算机辅助教学系统HICAI的设计思想、体系结构及各组成模块的功能。