Monitoring hypertext users

This paper reports a study to investigate the feasibility of using techniques of learner modelling from intelligent tutoring systems to support users of hypertext systems. The problems of disorientation experienced by hypertext users may be less significant in educationally realistic settings than suggested by previous studies. As a result of our study we conclude that (1) users are rather good at monitoring their own use of a hypertext system and (2) provided that the user's goals and expert paths through the database are both known, then the system, by the overlay modelling technique, may successfully monitor the user's actions.     

Implementing an open link service for the World Wide Web

Links are the key element for changing a text into a hypertext, and yet the WWW provides limited linking facilities. Modeled on Open Hypermedia research the Distributed Link Service provides an independent system of link services for the World Wide Web and allows authors to create configurable navigation pathways for collections of WWW resources. This is achieved by adding links to documents as they are delivered from a WWW server, and by allowing the users to choose the sets of links that they will see according to their interests. This paper describes the development of the link service, the facilities that it adds for users of the WWW and its specific use in an Electronic Libraries project.     

MOSAICA: A web-2.0 based system for the preservation and presentation of cultural heritage

The question of how to present cultural heritage resources in a way that attracts potential users is becoming important in our ever-changing world. This paper describes MOSAICA system – a web 2.0-based toolbox, dedicated for the preservation and presentation of cultural heritage. This paper also describes an evaluation study that examined MOSAICA system’s usability and social impact. Online questionnaires and semi-structured interviews were administered among users from Israel, France, and Poland. Findings indicated positive views related to MOSAICA’s usage in terms of knowledge gain, ease of use, and attractiveness. Findings also indicated that learning about the stories, customs, and traditions of diverse cultures, via hypertext narratives, may enhance positive dispositions toward open-mindedness, in general, and non-judgmental views, in specific. MOSAICA system provides a generic framework for users, of any culture and religion, to actively engage in preserving their heritage via activities such as investigation, exploration, and storytelling.     

Sleuthing in HyperHolmes : aTM an evaluation of using hypertext vs. a book to answer questions

Although hypertext offers exciting new ways of presenting and accessing information, there is little research which systematically compares the usability of hypertext against traditional media with an eye to improving the design of the hypertext. This paper presents the results of an experiment which examined the performance and navigation strategies of users engaged in a question-answering task using either a hypertext encyclopedia of Sherlock Holmes facts (the HyperHolmessy^TMstem) or the traditional paper form. The results showed that, overall, the hypertext users were marginally more accurate in answering questions, and excelled at questions where the key information was embedded in a text entry. The book users were marginally faster overall, but excelled only in answering questions based on graphics. Hypertext users showed a preference for those tools which most closely mimicked use of a conventional book. They used a hierarchical structure to guide their navigation strategy in early trials, but soon learned to navigate in a non-hierarchical, flat way.     

Interacting With Hypertext: A Meta-Analysis of Experimental Studies

The meta-analysis compared and synthesized the results of 23 experimental studies on hypertext. The analysis was based on 56 pairs of effect sizes and significance levels of the impact of users, tasks, and tools on interactions with hypertext. This analysis focused on three factors that prevailingly influence the use of hypertext: the cognitive styles and spatial ability of users; the complexity of tasks; and the structure of information organization and the visualization of the structure. The meta-analysis found that this group of experimental studies reported significantly discrepant findings, indicating that substantial differences exist among individual experiments. Individual differences in cognition did not yield enough evidence to conclude that the effect sizes are significantly apart from zero. The meta-analysis showed that the overall performance of hypertext users tended to be more effective than that of nonhypertext users, but the differences in efficiency measures were consistently in favor of nonhypertext users. Users benefited more from hypertext tools for open tasks. Overall, the complexity of tasks has the largest combined effect sizes. Graphical maps that visualize the organization of hypertext have significant impact on the usefulness of a hypertext system. This meta-analysis raised two issues concerned with the present hypertext literature: (a) the absence of a taxonomy of tasks for analyzing and comparing hypertext usability across studies, and (b) the weaknesses of the connections between abstract hypertext reference models and specific hypertext systems. These weaknesses may considerably undermine the significance of individual findings on hypertext usability. Results of the meta-analysis suggest that the discrepancies among empirical findings are related to these weaknesses. Future work on hypertext usability should emphasize task taxonomies along with longitudinal and ethnographic studies for a deep understanding of the interactions between users and hypertext. Recommended research issues for the future are highlighted in Section 5.     

Task-based method for creating usable hypertext

Although large hypertext documentation systems have many benefits in the commercial world, they can be difficult to build and use. To help overcome both these obstacles, a method under development at Hewlett-Packard assists authors in creating usable hypertext. A Wizard of Oz experiment was done with traditional on-line documentation and hypertext documentation to see what users liked and disliked. The experiment showed the need for a set of hypertext construction rules to ensure usability. Following these rules, and with computer assistance, authors are expected to do a task analysis of users' activities, to identify critical objects and create content nodes for them, to create links between nodes within clearly defined and cognitively justified limits, and to conduct usability tests on the resulting hypertext volume. Whilst this method recognises the importance of good clear writing, the rules and suggested prectices are not primarily about writing or screen design, but about creating a coherent navigational web that ensures success among commercial users of hypertext. The authoring system described in this paper has been developed for the HP Help system, which has been adopted as the common help delivery system for developers of Common Open Systems Environments on Unix-like platforms.     

Retrieving information from hypertext: issues and problems

One of the most important developments in information science and in information systems in recent years has been the emergence of hypertext as a way of organizing information. Hypertext uses a browsing rather than a searching strategy and hypertext systems have found applications in a number of diverse areas. One of the strengths of using a hypertext system is the freedom it gives to users in the choice of information they wish to see, but this is also one of its drawbacks. This paper examines the effectiveness of hypertext as a way of retrieving information and reviews conventional information retrieval techniques which are the alternative strategy. Previous attempts at combining information retrieval and hypertext are considered and a prototype system outlined which has been developed to generate guided tours for users, to direct them through a hypertext to information they have requested. Finally, how adding this kind of intelligent guidance to a hypertext system would affect its usability as an information system is discussed.     

Incorporating String Search in a Hypertext System: User Interface and Signature File Design Issues

Hypertext systems provide an appealing mechanism for informally browsing databases by traversing selectable links. However, in many fact finding situations string search is an effective complement to browsing. This paper describes the application of the signature file method to achieve rapid and convenient string search in small personal computer hypertext environments. The method has been implemented in a prototype, as well as in a commercial product. Performance data for search times and storage space are presented from a commercial hypertext database. User interface issues are then discussed. Experience with the string search interface indicates that it was used successfully by novice users.     

Tailoring Automatically Generated Hypertext

This paper describes an approach for tailoring the content and structure of automatically generated hypertext. The implemented system HYLITE is based on applied Natural Language Generation (NLG) techniques, a re-usable user modelling component (VIEWGEN), and a flexible architecture with module feedback. The user modelling component is used by the language generation modules to adapt the hypertext content and links to user beliefs and preferences and to the previous interaction. Unlike previous adaptive NLG systems, which have their own, application-specific user models, HYLITE has re-used a generic agent modelling framework (VIEWGEN) instead. Apart from avoiding the development costs of a new model, this also enabled a more extendable system architecture. Another distinct feature of our approach is making NLG techniques adaptable by the user, i.e., providing users with control over the user model and the hypertext adaptivity.     

Elements and implications of a hypertext pedagogy

This paper describes elements of a pedagogy for writing hypertext stories in year eight classes in secondary schools. Over a period of 18 months, 100 students in three schools completed handwritten and hypertext stories. The pedagogical elements identified include the use of pictures in hypertexts, collaboration, screen-based writing, non-linear writing and student oral presentations of hypertext stories with an LCD projector. Some future trends in students' hypertext writing research are identified. The paper argues that the teaching practices described challenge accepted notions of teaching.     

超媒体系统中的一种图形对象数据模型

本文在分析了图形媒体对象结构的基础上，运用Ｄｅｘｔｅｒ超文本参考模型建立起一种图形对象的数据模型。在该模型中，通过概括和建立起对象的共享属性和操作机制；对象成员存储结构中的锚定点支持层、图元和区域热对象，属性集定义图形对象的类型和检索特性；图形成员对象的实例化向用表现多媒体成员，利用表现规范和锚定点的可视表示提供用户的交互、信息迁移和图元变换表现，实现编辑函数可以保存用户对图形成员对象的修改。     

Results of the Hypertext '89 Design Survey

For authors to write and maintain large hyperdocuments, hypertext systems must provide abstractions at a higher level than a link.

This paper presents one example of such an abstraction: the hypertext equivalent of the procedure call with arguments. The paper describes why such a facility is needed, and how it has been implemented in the UNIX implementation of the Guide hypertext system     

Trams: Transportation-related air-management system

Transportation and air-quality issues are complex, coupled with the dynamic evolution of regulations, trends, and implications. The need for planners and decision makers to access current and expert information on air-quality trends, transportation planning, and applicable legislation to assist them in transportation-related air-quality management encouraged the development of the Transportation-Related Air-Management System (TRAMS). This hypertext, hypermedia system enables planners and decision makers to dynamically retrieve current information at their desktops. Transportation and air-quality information on a wide variety of related topics is organized into a branching hierarchy and presented in a consistently structured hypertext environment, allowing users to direct their own path through the resources integrated in the system design including graphics, glossary terms, crossreferences, original text materials, and expert contact information.     

Introducing hypertext in primary health care: a study on the feasibility of decision support for practitioners

A study on the feasibility of the introduction of hypertext systems for communication of medical knowledge in primary care is described. Shortliffe's constraints on areas for application of decision support are evaluated (i.e., theoretical barriers, observable and recognized needs among users, sources of usable knowledge, available system development method). Considering the barriers derived from the knowledge types and forms used by practitioners, hypertext was found suitable as support at 'breakdowns' in practice routines, to generate 'alarms', as well as for continued medical education. A survey of the a priori acceptance of decision support systems by general practitioners showed that 84% would use the computer support if it was available today and that full-text databases, such as hypertext, were given highest priority for introduction. Local specialist physicians were identified as knowledge sources for therapy advice. Implementation of prototype systems envisioned use of hypertext in primary care as the introduction of a communication medium for co-operative health care decision making. A model for the introduction into the work environment is described.     

Understanding corporate data models

Corporate data models are widely used to support data management within organisations. However, both IS professionals and business users find them difficult to understand. This paper describes a methodology for designing and representing corporate data models that uses explanation and visualisation mechanisms to improve understanding, and reports a case study of the use of the methodology in the development of a data warehouse. The methodology was shown to be effective in that a high quality corporate data model was designed and then understood and utilised by all the participants. The model was used as an active, hypertext interface to the first prototype of the data warehouse. The case study findings indicated that: scenarios are useful for eliciting information requirements and explaining abstract concepts in the model to business users; graphical icons and subject area partitions are effective means of visualising the model and lead to improved understanding of the model by business users; and design rationale is an effective means of explaining the evolution of concepts in the model for specialist data modellers.     

Effectiveness of expert semantic knowledge as a navigational aid within hypertext

Hypertext systems parse documents into content nodes connected by machine supported links or relationships. Many hypertext researchers claim that the node-link relationships of hypertext provide an information organization that models the structure of human knowledge and should therefore facilitate information access (Fiderio 1988). Yet, failures of information access occur when users lack an understanding of the overall scope and organization of a hypertext system (Gay and Mazur 1991). To support this understanding, the present research incorporated expert-based domain semantics in the design of prosthetic devices for hypertext navigation. The task domain was documentation for a word processing system. In the first experiment, the pathfinder algorithm (Schvaneveldt 1990) and cluster analysis were used to identify a set of expertbased semantic relationships between word-processing concepts. The results from these analyses contributed to the design of two prostheses to assist hypertext navigation: A hierarchical index and a local semantic browser. These aids were tested in a second experiment, crossing type of on-line documentation (semantically enhanced hypertext or an alphabetically indexed text) with level of subject expertise (novice or expert). Both performance and strategy measures suggest that the semantic prostheses improved the accessibility of information for novice users without hampering expert performance.     

Evaluation of hypertext in an activity learning environment

Abstract This paper presents a study which evaluates the use and efficiency of two computer learning tools for basic virology. The first, VIROLAB, is a simulation of a biology laboratory in which the learner uses virtual lab facilities to help defective viruses to multiply. The system also includes a hypertext that provides learners with some knowledge on virology. The second tool is the hypertext which has been extracted from VIROLAB and which is now considered as an independent learning environment. This study addressed two specific questions: (1) which of the two tools was the most efficient for knowledge acquisition, and (2) were there any differences in the use of the two hypertexts? Comparison of pre‐ and post‐test scores showed that neither of the two learning tools is better than the other. However, analysis of the navigation paths showed that VIROLAB users dissociated the reading of the integrated hypertext from the problem resolution activities. The implications of this finding for the design of the learning environment are discussed.     

Review: An information management system for informal design data

Engineering information management may be divided into formal information management, which involves data modelling, data exchange and transaction handling, and informal information management, which is concerned with the organisation and delivery of design advice and design parameter data. This paper describes a system, called Review, which has been developed for the management of informal design information from multiple sources. The system uses a hybrid hypertext/database approach to provide for the indexing and viewing of information sources using arbitrary attribute sets, and for the establishment of relationships between information entities using both static and dynamic links in a hypertext framework. Information may be accessed both by query and by browsing along relationships in the hypertext network. The paper presents an overview of the system design, and examples of its application to design advisory systems and documentation.     

Effectiveness of expert semantic knowledge as a navigational aid within hypertext

Hypertext systems parse documents into content nodes connected by machine supported links or relationships. Many hypertext researchers claim that the node-link relationships of hypertext provide an information organization that models the structure of human knowledge and should therefore facilitate information access (Fiderio 1988). Yet, failures of information access occur when users lack an understanding of the overall scope and organization of a hypertext system (Gay and Mazur 1991). To support this understanding, the present research incorporated expert-based domain semantics in the design of prosthetic devices for hypertext navigation. The task domain was documentation for a word processing system. In the first experiment, the pathfinder algorithm (Schvaneveldt 1990) and cluster analysis were used to identify a set of expertbased semantic relationships between word-processing concepts. The results from these analyses contributed to the design of two prostheses to assist hypertext navigation: A hierarchical index and a local semantic browser. These aids were tested in a second experiment, crossing type of on-line documentation (semantically enhanced hypertext or an alphabetically indexed text) with level of subject expertise (novice or expert). Both performance and strategy measures suggest that the semantic prostheses improved the accessibility of information for novice users without hampering expert performance.     

Designing user interfaces for problem solving,with application to hypertext and creative writing

Interactive computer systems can support their users in problem solving, both in Performing their work tasks and in using the systems themselves. Not only is direct support for heuristics beneficial, but to do so modifies the form of computer support provided. This Paper defines and explores the use of problem solving heuristics in user interface design.A demonstration hypertext system, Hyperwriter, was developed as the outcome of considering general problem solving heuristics as goals of interactive systems design. Whereas hypertext joins and relates ideas, Hyperwriter additionally, and as a direct outcome of the design approach, has ways of separating, ordering and polishing ideas. As an application for creative writing, Hypertext supports effective thinking over a period of time. (This paper was drafted, organised and re-organised using the system itself.) Some issues arising in implementing Hyperwriter are also discussed.