This thesis focuses on interactive and computational semantics for manipulating the time-based medium of an evolving information space. The interactive semantics enable the user to engage in linear timeline traversal and non-linear history manipulation. Extended tape recorder metaphor controls, including jog-shuttle based navigation, provide the user with flexible means for operating the software's generative functionalities, and linearly traversing session history. The user can see previews of information space states while traversing the history using the jog-shuttle. We also introduce a door-latch metaphor that enables one of several considered forms of nonlinear history manipulation. Users can change history by retroactively latching an information sample in its position across time. For representing the information space history, we have developed MPEG-like computational keyframe semantics. This representation is in the form of XML, which is generated automatically and converted back to Java by a framework named ecologylab.xml, which was developed as a part of this thesis. These computational keyframe semantics serve as the basis for interaction semantics. A user study was conducted in the form of a design competition, to evaluate these new features. The results indicated that the users do find the time travel features useful and they feel more in-control of the information space with access to time travel features compared to the case when time travel features are not present.

Information delivery on the Web often relies on general purpose Web pages that require the reader to adapt to them. This limitation is addressed by approaches such as spatial hypermedia and adaptive hypermedia. Spatial hypermedia augments the representation power of hypermedia and adaptive hypermedia explores the automatic modification of the presentation according to user needs. This dissertation merges these two approaches, combining the augmented expressiveness of spatial hypermedia with the flexibility of adaptive hypermedia. This dissertation presents the Multi-model Adaptive Spatial Hypermedia framework (MASH). This framework provides the theoretical grounding for the augmentation of spatial hypermedia with dynamic and adaptive functionality and, based on their functionality, classifies systems as generative, interactive, dynamic or adaptive spatial hypermedia. Regarding adaptive hypermedia, MASH proposes the use of multiple independent models that guide the adaptation of the presentation in response to multiple relevant factors. The framework is composed of four parts: a general system architecture, a definition of the fundamental concepts in spatial hypermedia, an ontological classification of the adaptation strategies, and the philosophy of conflict management that addresses the issue of multiple independent models providing contradicting adaptation suggestions. From a practical perspective, this dissertation produced WARP, the first MASH-based system. WARP’s novel features include spatial transclusion links as an alternative to navigational linking, behaviors supporting dynamic spatial hypermedia, and personal annotations to spatial hypermedia. WARP validates the feasibility of the multi-model adaptive spatial hypermedia and allows the exploration of other approaches such as Web-based spatial hypermedia, distributed spatial hypermedia, and interoperability issues between spatial hypermedia systems. In order to validate the approach, a user study comparing non-adaptive to adaptive spatial hypertext was conducted. The study included novice and advanced users and produced qualitative and quantitative results. Qualitative results revealed the emergence of reading behaviors intrinsic to spatial hypermedia. Users moved and modified the objects in order to compare and group objects and to keep track of what had been read. Quantitative results confirmed the benefits of adaptation and indicated a possible synergy between adaptation and expertise. In addition, the study created the largest spatial hypertext to date in terms of textual content.

<p>Tendensen hos pedagogisk hypermedia är att man har tagit fasta på de eventuella effekter som interaktionen i sig anses ha. Med interaktion i det här avseendet åsyftas i mångt och mycket programmets "klickbarhet". Klickbarheten möjliggör för eleven att delta i undervisningen genom att styra avsnittens ordning, svara på frågor, m.m. Denna typ av delaktighet i undervisningen som tekniken erbjuder borde kunna utvecklas och även användas vid tillämpandet av traditionellt inlärningseffektiviserande metoder.</p><p>Inom forskning kring traditionell lärarledd undervisning finns en mängd teorier som pekar på att metakognition är av stor betydelse vid inlärning generellt. Med metakognition avses tänkandet på hur man tänker. I en inlärningssituation representeras det metakognitiva tänkandet av tankar om hur man skall tänka för att lära sig. Denna studie har för avsikt att hitta en teknik för att understödja metakognition vid inlärning i hypermedia. Inlärningseffekten skall studeras hos två grupper, där den ena använder en metakognitionsmetod och den andra en repetitionsmetod.</p>

DOI: 10.1016/S0306-4573(98)00065-X / There was a proliferation of electronic information sources and search engines in the 1990s. Many of these information sources became available through the ubiquitous interface of the Web browser. Diverse information sources became accessible to information professionals and casual end users alike. Much of the information was also hyperlinked, so that information could be explored by browsing as well as searching. While vast amounts of information were now just a few keystrokes and mouseclicks away, as the choices multiplied, so did the complexity of choosing where and how to look for the electronic information. Much of the complexity in information exploration at the turn of the twenty-first century arose because there was no common cataloguing and control system across the various electronic information sources. In addition, the many search engines available differed widely in terms of their domain coverage, query methods, and efficiency. Meta-search engines were developed to improve search performance by querying multiple search engines at once. In principle, meta-search engines could greatly simplify the search for electronic information by selecting a subset of first-level search engines and digital libraries to submit a query to based on the characteristics of the user, the query/topic, and the search strategy. This selection would be guided by diagnostic knowledge about which of the first-level search engines works best under what circumstances. Programmatic research is required to develop this diagnostic knowledge about first-level search engine performance. This paper introduces an evaluative framework for this type of research and illustrates its use in two experiments. The experimental results obtained are used to characterize some properties of leading search engines (as of 1998). Significant interactions were observed between search engine and two other factors (time of day, and Web domain). These findings supplement those of earlier studies, providing preliminary information about the complex relationship between search engine functionality and performance in different contexts. While the specific results obtained represent a time-dependent snapshot of search engine performance in 1998, the evaluative framework proposed should be generally applicable in the future.

The term â hypertextâ evokes many images (e.g., nodes and links, semantic webs, non-linear access and so forth) but perhaps one of the most common is that of users struggling to find their way around a complex information space. As a result, navigation has become a subject of great interest to many researchers in the field. In this chapter we will discuss navigation through hypertext in terms of its relevance as a concept as much as its presence as an issue and try to draw lessons for design and research from the psychological work that has been carried out on navigation in physical space. We will attempt to show that while relevant to hypertext, discussion of navigation is prone to difficulty when researchers and designers misapply arguments and evidence from the physical domain to the semantic domain.

This position paper argues that the Web 2.0 phenomenon is an important object of study for information systems research, and that a social informatics approach to understanding Web 2.0 is particularly relevant and useful. We discuss Wikipedia as an example of empirical research on Web 2.0 that can help bridge the divide between academic and popular discourse on new technology movements.

This item is not the definitive copy. Please use the following citation when referencing this material: Dillon, A. (2001) Usability evaluation. In W. Karwowski (ed.) Encyclopedia of Human Factors and Ergonomics, London: Taylor and Francis. Introduction: Usability is a measure of interface quality that refers to the effectiveness, efficiency and satisfaction with which users can perform tasks with a tool. Evaluating usability is now considered an essential part of the system development process and a variety of methods and have been developed to support the human factors professional in this work.

This position paper argues that the Web 2.0 phenomenon is an important object of study for information systems research, and that a social informatics approach to understanding Web 2.0 is particularly relevant and useful. We discuss Wikipedia as an example of empirical research on Web 2.0 that can help bridge the divide between academic and popular discourse on new technology movements.

This item is not the definitive copy. Please use the following citation when referencing this material: McKnight, C., Dillon, A. and Richardson, J. (1992) Hypermedia. In A. Kent (Ed.) Encyclopedia of Library and Information Science, Vol. 50, New York: Marcel Dekker, 226-255. Overview: The field of hypertext/hypermedia has mushroomed so much in the last five years that an article such as this cannot hope to be all-embracing. Rather, what we will do is provide a perspective on hypertext/hypermedia while offering guidance to the published literature. The perspective we give is essentially user-centred since we believe that ultimately it is user issues which will determine the success or failure of any technology. We begin with a brief introduction and history then draw together some of the relevant research which has a bearing on hypertext/hypermedia usability. Some of this research has been conducted specifically in the field of hypertext but some general human-computer interaction research also needs to be considered. We look briefly at some of the issues involved in creating hypertexts and also at some of the claims made for hypertext. Finally, we attempt to see what the future holds for hypertext and offer a list of further reading.

This item is not the definitive copy. Please use the following citation when referencing this material: Dillon, A., Richardson, J. and McKnight, C. (1989) The human factors of journal usage and the design of electronic text. Interacting with Computers, 1(2), 183- 189. Abstract: The present paper reports on a study of journal usage amongst human factors researchers. The aim of the study was to shed light on how journals are used with a view to making recommendations about the development of a full-text, searchable database that would support such usage. The results indicate that levels of usage vary over time, the range of journals covered is small and readers overlook a large proportion of the contents of articles. Furthermore, three reading strategies are observed which indicate that the presentation of journal articles is not ideally suited to their uses. The implications of these findings for developing suitable computer-based applications are discussed.