Hypertext Systems Research Articles

ALPS (A Language for Process Specification) – A definition language for hypertext trails

This paper proposes using ALPS to specify a new hypertext trail to an existing hypertext document. In Vannevar Bush's first hypertext system “Memex”, Bush envisioned “Memex” as having the ability for a user to define a trail in an information space.

The Knowledge Adventure

The Knowledge Adventure

Electronic document addressing

The management of electronic document collections is fundamentally different from the management of paper documents. The ephemeral nature of some electronic documents means that the document address (i.e., reference details of the document) can become incorrect some time after coming into use, resulting in references, such as index entries and hypertext links, failing to correctly address the document they describe. A classic case of invalidated references is on the World Wide Web—links that point to a named resource fail when the domain name, file name, or any other aspect of the addressed resource is changed, resulting in the well-known Error 404. Additionally, there are other errors which arise from changes to document collections. This paper surveys the strategies used both in World Wide Web software and other hypertext systems for managing the integrity of references and hence the integrity of links. Some strategies are preventative , not permitting errors to occur; others are corrective , discovering references errors and sometimes attempting to correct them; while the last strategy is adaptive , because references are calculated on a just-in-time basis, according the current state of the document collection.

Lost in hyperspace: metrics and mental models

Being disorientated or lost is one of the fundamental difficulties which users experience when trying to navigate within hypertext systems. In this paper, two new metrics of lostness are described and applied. The new metrics focus on the effects of link-type and the accuracy of user's mental models of system structure. In a series of studies, the new metrics were compared with the only other published metric of lostness, the optimal path deviation measure formulated by Smith [P.A. Smith, Towards a practical measure of hypertext usability, Interacting with Computers 4 (1996) 365–381], and with other measures including self-report estimates and task times. The results tentatively suggest that some types of hyperlink have a greater impact on lostness than others. The accuracy of the subjects’ mental models did not correlate significantly with other measures of lostness, however this may have been due to task demands. Based on these findings, suggestions are made for the design of more effective hypertext systems that minimise lostness, and a new approach to designing such systems, based on the mental models of users, is put forward.

Relative advantage of portable computer-based workcards for aircraft inspection

Following a successful demonstration of the applicability of human factors guidelines to the design of aircraft maintenance documentation (Patel et al., 1994, Applied Ergonomics, 25 (5) 286 – 293) a natural extension was to replace paper-based workcards with a computer system. Using additional human factors guidelines for design of computer systems, a prototype hypertext system was developed for use on a portable computer. A number of different workcards were accommodated, and an evaluation made of the computer-based workcard against both original and improved paper-based workcards. For the task studied, eight inspectors rated the computer-based system highly on scales derived from the guidelines. The computer-based system was a significant improvement over the original paper-based workcards. Relevance to industry Process documentation and work instructions need to be used in many industries, particularly those certified under the ISO-9000 series of standards. An obvious way to improve the management of documentation is to deliver it to the user electronically. This paper shows how the user interface to such a system can be designed.

NED-1: integrated analyses for forest stewardship decisions

NED is a collective term for a set of software intended to help resource managers develop goals, assess current and potential conditions, and produce sustainable management plans for forest properties. The software tools are being developed by the USDA Forest Service, Northeastern and Southern Research Stations, in cooperation with many other collaborators. NED-1 is a Windows-based program that helps analyze forest inventory data from the perspective of various resources on management areas as large as several thousand hectares. Resources addressed include visual quality, ecology, forest health, timber, water, and wildlife. NED-1 evaluates the degree to which an individual stand or an entire management unit may provide the conditions required to accomplish specific goals. NED-1 users select from a variety of reports, including tabular data summaries, general narratives, and goal-specific analyses. An extensive hypertext system provides information about the resource goals, the desired conditions that support achieving those goals, and related data used to analyze the actual condition of the forest, as well as detailed information about the program itself and the rules and formulas used to produce the analyses. The software is constructed in C++ using an application framework; the inferencing component that handles the rule bases uses Prolog.

P-Compatible Hypersubstitution and MP-Solid Varieties

The study of hyperidentities is a growing field of research. While hyperidentities hark back to before 1965 (cf. [1]), they have found a rebirth in the late seventies and early eighties (cf. [8], [9]). It is being expanded in several directions, from connections with clone theory, to finite basis problems, to semigroup theory, to classification of M-solid varieties. Applications to digital logic, formal languages, and hypertext systems have been suggested. The concept of a P-compatible equation, where P is a partition on the set of operation symbols, is a good tool to study the structure of identities. In [4] we asked for P-compatible hyperidentities.

Measuring Navigational Preference in Hypertext Systems for Distributed Learning

This article reports the results of a usability study of a hypertext learning system developed at the Florida State University School of Information Studies. The method employed in this study was based on earlier usability studies of hypertext systems conducted by P. A. Smith and extended by the authors to include a new measure of navigational preference. The navigational preference measure employs concept mapping to determine the user's preferred navigational path and compares this to the optimal path as designed by the system designers. The results of the study indicate that this new measure is effective and makes a significant contribution to the understanding of usability of hypertext learning systems. A further study is currently being conducted to validate the results of the study reported.

Navigable history: a reader's view of writer's time

Collecting, analyzing, and sharing information via a hypertext results in the continuous modification of information content over a long period of time. Such tasks will benefit from users having access to this authoring process. The Visual Knowledge Builder (VKB), a spatial hypertext system designed to support collaborative knowledge building, includes navigable history to provide readers a view of the writer's time. VKB acts as a workspace for collecting, organizing, and interpreting information in a hierarchy of two-dimensional planes. During authoring, VKB records events in the hypertext's history and provides methods to access prior states of the hypertext. The reader may play forward or backward through the authoring process as well as search for a variety of authoring events on information objects. Users receive cues about the absolute and relative timelines of the information space through the presentation of information about specific events and their sequence. Examples of VKB's use include note taking, writing, organizing conferences, and sharing information in a research group. Analysis of VKB workspaces in these contexts indicates navigable history supports 1) learning and interpreting authors’ work practices, 2) recognizing patterns of activity in the information space, and 3) disambiguating specific actions and content. Hypertexts that include an authoring history add a notion of constructive time for their readers.

Mind the eyel On the relevance of composition in spatial organization

This paper focuses on the relationship between semantics and aesthetics in spatial hypertext. The author departs from the observation that certain metaphors from the GUI world have a stronger effect on spatial hypertext than on other information systems. It is argued that the human desire to compose objects on a picture plane not only due to semantic, but also due to aesthetic principles, counteracts the construction of meaning. The author intends to encourage a discussion about the tension between finished presentational structures and working interpretive structures in spatial hypertext systems. The grounding of this discussion are art theory, psychology and other non-hypertext sources.

Navigation in Hypertext Is Easy Only Sometimes

One of the main unsolved problems confronting Hypertext is the navigation problem, namely, the problem of having to know where you are in the database graph representing the structure of a Hypertext database, and knowing how to get to some other place you are searching for in the database graph. In order to tackle this problem we introduce a formal model for Hypertext. In this model a Hypertext database consists of an information repository, which stores the contents of the database in the form of pages, and a reachability relation, which is a directed graph describing the structure of the database. The notion of a trail, which is a path in the database graph describing some logical association amongst the pages in the trail, is central to our model. We define a Hypertext query language for our model based on a subset of propositional linear temporal logic, which we claim to be a natural formalism as a basis for establishing navigation semantics for Hypertext. The output of a trail query in this language is the set (which may be infinite) of all trails that satisfy the query. We show that there is a strong connection between the output of a trail query and finite automata in the sense that, given a Hypertext database and a trail query, we can construct a finite automaton representing the output of the query, which accepts a star-free regular language. We show that the construction of the finite automaton can be done in time exponential in the number of conjunctions, between the subformulas of the trail query, plus one. Given a Hypertext database and a trail query, the problem of deciding whether there exists a trail in the database that satisfies the trail query is referred to as the model checking problem. We show that, although this problem is NP-complete for different subsets of our query language, it can be solved in polynomial time for some significant special cases. Thus the navigation problem can only be efficiently solved in some special cases, and therefore in practice Hypertext systems could include algorithms which return randomized and/or fuzzy solutions.

Trends, fashions, patterns, norms, conventions . . . and hypertext too

This article describes the theoretical approach behind the InCommonSense system. This approach makes use of writing conventions on the Web. The theory behind InCommonSense is based on research findings from the fields of linguistics, psychology, HCI, sociology, and information retrieval. The theoretical background for finding and reusing conventions in hypertext is discussed, and the possibilities of extending the system to improve existing hypertext systems and creating new futuristic hypertext meanings (in particular on the Web) are examined.

The Evaluation of a Personalised Health Information System for Patients with Cancer

In this paper we describe the evaluation of a personalised information system for patients with cancer. Our system dynamically generates hypertext pages that explain treatments, diseases, measurements etc related to the patient's condition, using information in the patient's medical record as the basis for the tailoring. We describe results of a controlled trial comparing this system with a nonpersonalised one. The results of the trial slow significant results concerning the patients' preferences for personalised information. We discuss the implications of our evaluation and results for the development and evaluation of future personalised systems, and adaptive hypertext systems in particular.

Decision Support for Indexing and Retrieval of Information in Hypertext Systems

This study introduces and evaluates the performance of two statistical models intended to support the automatic creation of a subject-based index containing links to hypertext documents. The fuzzy Bayes model makes strong dependence assumptions, and only considers the strongest evidence presented by single words occurring in a document, whereas the classic Bayes model makes strong independence assumptions and attempts to aggregate all the evidence. The links or index terms suggested by both indexing models overlapped greatly with those assigned by a human indexer. However, the probabilities calculated using the classic Bayes model were unstable because of data sparseness and severe violations of the independence assumptions. Subsequent analysis therefore focused on the fuzzy Bayes model. The latter analysis revealed that human experts rated index terms suggested by the model significantly higher than randomly selected index terms. When the index terms assigned by the fuzzy Bayes model were implemented as links in a hypertext system, users' performance on information retrieval tasks was similar to that using links assigned by the human indexer. These results demonstrated that the fuzzy Bayes model is a particularly promising method that can accurately duplicate the links suggested by a human indexer, requires little computation, and offers the potential advantage of flexibly modifying links in a way that reflects the relative costs of false alarms and misses.

Where have you been from here? Trials in hypertext systems

article Free Access Share on Where have you been from here? Trials in hypertext systems Authors: Siegfried Reich University of Southampton, Multimedia Research Group, Highfield Lane, Southampton, SO17 1BJ, UK University of Southampton, Multimedia Research Group, Highfield Lane, Southampton, SO17 1BJ, UKView Profile , Leslie Carr University of Southampton, Multimedia Research Group, Highfield Lane, Southampton, SO17 1BJ, UK University of Southampton, Multimedia Research Group, Highfield Lane, Southampton, SO17 1BJ, UKView Profile , David De Roure University of Southampton, Multimedia Research Group, Highfield Lane, Southampton, SO17 1BJ, UK University of Southampton, Multimedia Research Group, Highfield Lane, Southampton, SO17 1BJ, UKView Profile , Wendy Hall University of Southampton, Multimedia Research Group, Highfield Lane, Southampton, SO17 1BJ, UK University of Southampton, Multimedia Research Group, Highfield Lane, Southampton, SO17 1BJ, UKView Profile Authors Info & Claims ACM Computing SurveysVolume 31Issue 4esDec. 1999 pp 11–eshttps://doi.org/10.1145/345966.345994Online:01 December 1999Publication History 12citation751DownloadsMetricsTotal Citations12Total Downloads751Last 12 Months3Last 6 weeks0 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF

Grammar and hypertext: building blocks of adult second language grammar mediation through a hypertext package (The A to Z of Grammar) in relation to current theories of adult second language acquisition/learning and the structural features of hypertext systems

This article argues that grammar has a role to play in adult second language (L2) learning and puts forward the hypothesis that the didactic spiral of language teaching can be most easily imitated by hypertext systems whose organisational structure is similar to that of language systems in its multi-layered form. It looks at the structural properties of hypertext and the organisation of information within hypertext systems which make hypertext packages not only suitable as independent learning tools but also particularly pertinent to the mediation of L2. Using a hypertext grammar package developed at the University of North London, we demonstrate how the structural properties of hypertext systems have been used for the mediation of the systematic aspects of language and how the design adapts to pedagogic requirements. This is related to a review of theoretical positions on L2 acquisition/learning with particular emphasis on the issues relevant to adult L2 learners. The article identifies the role of formal instruction in the various theories on L2 learning, in which way this affects the mediation of grammar and shows how this package fits into the various stages of L2 learning/acquisition, supporting the needs of different models of L2 development.

Integrational Aspects of a Knowledge-Based Assistance System in Psychiatry

Most classical medical expert systems suffer from a lack of impact on clinical routine. An alternative approach to computer-based decision support is discussed, which leads to the specification of knowledge-based assistance systems. The paper investigates integrational aspects of such assisting instruments. Organisational integration and clinical acceptance are improved by starting with an established clinical knowledge repository. The corresponding knowledge access strategies are analysed and carefully substituted by more efficient knowledge-based techniques. The approach has been applied to the DSM-IV Assistant, a knowledge-based hypertext system based on the Diagnostic and Statistic Manual of Mental Disorders (DSM-IV).

Step‐by‐step guideline for designing and documenting the navigation structure of multimedia hypertext systems

Most traditional navigational design techniques do not provide a good mechanism for dealing with the complexity of the navigational path of multimedia hypertext (or hypermedia) systems, such as a multimedia page on the Web. When the number of pages (or nodes) of the hypermedia system grows, the links among these pages increase factorially. This makes the navigation structure diagram of a small 20‐page Web site almost impossible to read, maintain, expand and reuse. In addition, most of these techniques do not provide formal instruction, or a step‐by‐step guideline, for users to support their development of hypermedia systems. This paper, therefore, aims to introduce, step‐by‐step, a new graph‐based navigational design technique, the Navigational Graph, together with a new set of notation. It provides systems developers to visualise and manipulate the navigational structures of Web sites. This technique improves the reusability, maintainability, decomposability, readability and expandability of the development of Web sites in terms of navigational design. This paper also attempts to address the problem of lack of guidelines for users to design and document their Web sites.

Thermal analysis of buildings in a mathematical programming environment and applications

An approach for computer-aided thermal analysis of buildings in a high level mathematical programming environment is presented with typical applications. It is based on a set of independent files organized through a hypertext system as an electronic book in a mathematical programming environment. Each file (section), which covers a specific topic such as psychrometric calculations or heating load estimation, integrates live equations (the program), explanatory text and figures, as well as graphs linked dynamically to equations and data. Both equations and input data can be readily changed and the results are instantly updated within the same document, thus providing unique educational and research capabilities. Three applications are presented: analysis of a floor heated with an infrared radiant ceiling system, thermal control analysis of a heating system and calculation of the thermal admittance transfer functions for a wall. The main advantage over the use of black box building simulation programs is that the user consolidates in a single document the input data, the output data, and the model, thus having the capability to easily understand and change the model as well as the data. However, this flexibility may also be a disadvantage if the models are quickly changed without careful planning; this problem may be avoided if well documented versions of a section (file) are created after each modification.

The design and evaluation of hypertext structures for supporting design problem solving

Computer-based complex information systems are used increasingly more often, for a growing variety of purposes, in both educational and professional contexts. Since the effectiveness of information systems will largely depend on the particular purpose and the particular task context at hand, at least part of our research efforts should be directed at studying specific application areas. This paper reports a study on the use of hypertext information systems during architectural-design problem solving. Theoretical notions on design problem solving, such as distinguishing between a problem-structuring and a problem-solving phase, provide us with expectations about the changing informational needs during the design process. Specific information structures are proposed, incorporating design principles from learning research, to accommodate these informational needs. Results of an empirical study indeed showed interactions between design phase and information structure when separately inspecting the outcomes for problem structuring and problem solving. Educational implications include the use of a combination of hierarchical decomposition and cross-referencing for certain instructional goals, such as teaching complexity and abstraction.