Designing to Facilitate Browsing: A Look Back at the Hyperties Workstation Browser

Since browsing hypertext can present a formidable cognitive challenge, user interface design plays a major role in determining acceptability. In the Unix workstation version of Hyperties, a research-oriented prototype, we focussed on design features that facilitate browsing. We first give a general overview of Hyperties and its markup language. Customizable documents can be generated by the conditional text feature that enables dynamic and selective display of text and graphics. In addition we present: — an innovative solution to link identification: pop-out graphical buttons of arbitrary shape.

— application of pie menus to permit low cognitive load actions that reduce the distraction of common actions, such as page turning or window selection.

— multiple window selection strategies that reduce clutter and housekeeping effort. We preferred piles-of-tiles, in which standard-sized windows were arranged in a consistent pattern on the display and actions could be done rapidly, allowing users to concentrate on the contents.

     

Age differences in the performance of hypertext perusal as a function of text topology

The present study examined the extent to which age had impacts on the performance of hypertext browsing and navigation as a function of text topology. Twenty senior adults and 20 younger adults (mean ages = 68.95 and 23.60 respectively) participated in an experiment where three levels of text linearity were manipulated. Results showed the older adult accessed fewer numbers of text nodes than the younger counterpart, which suggests that the aged appear at a disadvantage in browsing breadth. The older adult's less oriented browsing was evidenced by the larger number of nodes repeatedly visited, particularly when the network topology was perused. As for navigation, older people experienced greater disorientation given that they searched more links to locate the target node. This age difference was mainly derived from the disorientation occurring at the hybrid and network levels, with the hybrid condition resulting in the severest navigation confusion due to its mixed text structure. Implications for the design of hypertext that accommodates the age differences are discussed.     

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.     

A Comparative Study of Computer-Based Document Manipulation Techniques

Techniques to aid the manipulation of a computer-based document were tested by a group of 38 novice users. The subjects were given a period of time to browse the document (which employed a simple book metaphor), and were subsequently given a set of goal-related tasks in a question/answer session. The techniques tested were sequential paging, index referral, text find and embedded hypertext links. In the latter case, 3 differing types of link mechanisms were assessed and compared with each other. It was found that sequential paging and index referral were the most commonly used of the techniques. Text find was employed more for goal-related tasks than for browsing. The hypertext link technique was generally unpopular, especially for goal-related tasks. In order to establish the importance of the text find technique, the effect on reading strategies without this facility was also investigated. For browsing operations, an increase in paging and a decrease in hypertext linking was observed. In the case of goal-directed searching, an increase was observed in paging and index referral techniques.     

Age differences in the performance of hypertext perusal as a function of text topology

The present study examined the extent to which age had impacts on the performance of hypertext browsing and navigation as a function of text topology. Twenty senior adults and 20 younger adults (mean ages = 68.95 and 23.60 respectively) participated in an experiment where three levels of text linearity were manipulated. Results showed the older adult accessed fewer numbers of text nodes than the younger counterpart, which suggests that the aged appear at a disadvantage in browsing breadth. The older adult's less oriented browsing was evidenced by the larger number of nodes repeatedly visited, particularly when the network topology was perused. As for navigation, older people experienced greater disorientation given that they searched more links to locate the target node. This age difference was mainly derived from the disorientation occurring at the hybrid and network levels, with the hybrid condition resulting in the severest navigation confusion due to its mixed text structure. Implications for the design of hypertext that accommodates the age differences are discussed.     

Visual preview for link traversal on the World Wide Web

This paper demonstrates a technique for augmenting current World Wide Web browser implementations with features found in classical hypertext applications but unknown to the World Wide Web community until now. An example implementation is shown using Netscape Navigator 4.x using JavaScript, dynamic HTML and Java. The implementation follows an architecture based on a proxy server which acts as a gateway between the Internet and the browsing client. Based on the detailed example, support for further features is discussed.     

Introduction

We describe an SQL relational database schema for representing the objects in HyperCard, along with a technique for automatically populating this schema from a HyperCard stack using the facilities in HyperTalk with calls to the database manager. The standard relational database query language SQL can then be used to perform more general hypertext searches than are possible with the string search feature found in most hypertext browsing environments. Semiautomatic updates of the content of a hypertext are also possible using SQL updates on the object representations in the database to trigger corresponding HyperCard updates on the objects themselves. We describe a prototype implementation and present several example queries and updates to motivate this approach. These techniques, although demonstrated here specifically using HyperCard and Oracle for Macintosh, are generally applicable to a wide range of hypertext systems and relational databases.     

Hypertext Access and the New Oxford English Dictionary

While hypertext access to the New Oxford English Dictionary would seem to be potentially beneficial, the conversion of such a text to a hypertext document and the generation of semantic links may not be feasible. Rather than attempting either the conversion of the text or the designation and storage of specific hypertext links, a prototype frontend called READER has been developed that provides hypertext access to the Dictionary. The emphasis in this work has been to provide the user with the browsing approach typical of hypertext rather than the more traditional query-oriented approach to accessing full-texts. The prototype is based on a dynamic hypertext model which facilitates browsing through the dynamic instantiation of implicit links existing in the text of the Dictionary.     

LΩUI: Lovely ΩMEGA User Interface

The capabilities of a automated theorem prover's interface are essential for the effective use of (interactive) proof systems. LΩUI is the multi-modal interface that combines several features: a graphical display of information in a proof graph, a selective term browser with hypertext facilities, proof and proof plan presentation in natural language, and an editor for adding and maintaining the knowledge base. LΩUI is realized in an agent-based client-server architecture and implemented in the concurrent constraint programming language Oz. Received November 1998 / Accepted in revised form June 1999     

HyperFile: A data and query model for documents

Non-quantitative information such as documents and pictures pose interesting new problems in the database world. Traditional data models and query languages do not provide appropriate support for this information. Such data are typically stored in file systems, which do not provide the security, integrity, or query features of database management systems. The hypertext model has emerged as a good interface to this information; however,finding information using hypertext browsing does not scale well. We developed a query interface that serves as an extension of the browsing model of hypertext systems. These queries minimize the repeated user interactions required to locate data in a standard hypertext system. HyperFile is a prototype data server interface. In this article, we describe HyperFile, including a number of issues such as query generation, query processing, and indexing.     

Automatic generation and refinement of hypertext links

Abstract

Current generation of hypertext systems suffer from the limitations that they are static in nature, and they do not support the automated process of link creation very well. Because of the efforts involved in manually creating links, the hyperbases created using these systems are seldom modified even when they were found not to fully support the requirements of the intended users. This paper studies the development of automated tools to aid in the process of link creation, browsing, and link refinement. Only relation links are considered in this study. The automated tools are developed to help in three of the major stages of developing and using hypertext applications: (a) during authoring to generate a set of relation links between pairs of nodes; (b) during browsing to recommend an optimal set of starting nodes for the users to begin browsing, and to guide the users at each stage of browsing by suggesting a set of “next” nodes to traverse; and, (c) during training to modify, remove and add links based on users' feedback data collected. The training will result in long-term changes in the hypertext structure.

In order to test the effectiveness of the training process objectively, a navigator is built to simulate the browsing activities of the users. The effects of training have been evaluated on two text collections using a variety of objective measures. The results indicate that the training process has improved the effectiveness of the hyperbase to support browsing.     

Effect of hypertext highlighting on browsing,reading, and navigational performance

Reading hypertext documents is more difficult than reading traditional linear text. Text highlighting plays the role of encoding for reading comprehension and may play the roles of contextual cues and landmarks for hypertext navigation. The purpose of this study was to examine the effect of text highlight and organizing highlighted text into a hierarchical structure on browsing, reading, and navigation performance in a network hypertext system. A randomized experiment was conducted. Ninety participants were randomly assigned to three conditions: a reading system with text highlighting, with text highlighting and organizing highlighted text, and without any aids. Dependent variables included browsing performance: time spent and the length of navigational path for reading; reading performance: recall and inference scores, navigational performance: scores of landmark and route knowledge and time spent and the length of navigational path for completing nine navigational tasks. The results showed that text highlight did not improve reading and navigational performance. By contrast, organizing highlighted text yielded significantly worst performance in reading and navigation. According to the results, we propose several suggestions for the design of reading instruction and digital highlighters.     

Information retrieval and hypertext: competing technologies or complementary access methods

Abstract. Information retrieval typically involves accessing textual information from a database in response to a user's vague information need. Hypertext or hypermedia, on the other hand, involves a user browsing through a database of textual or multimedia information in response to a variety of types of information need. Thus information retrieval can be said to have a searching metaphor while hypertext has a browsing analogy. Initially, these two technologies for information access appear to be very different, almost competitive in nature. In this paper information retrieval systems are briefly reviewed and hypertext systems are also examined. These two techniques for accessing information have been integrated into a prototype system which is described. The system dynamically generates guided tours in response to a user's query and the tour guides the user through the hypertext. Some experiments reporting on the effectiveness of this as an information access strategy are given.     

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.     

Hypadapter: An adaptive hypertext system for exploratory learning and programming

We have developed an adaptive hypertext system designed to individually support exploratory learning and programming activities in the domain of Common Lisp. Endowed with domain-specific knowledge represented in a hyperspace of topics, the system builds up a detailed model of the user's expertise which it utilizes to provide personalized assistance. Unlike other work emerging in the field of adaptive hypertext systems, our approach exploits domain and user modelling techniques to support individuals in different ways. The system not only generates individualized presentations of topic nodes, but also provides adaptive navigational assistance for link-based browsing. By identifying and suggesting useful hyperlinks according to the user's knowledge state and preferences, the system encourages and guides exploration. While browsing through the hyperspace of topics, the system analyses the user's navigational behaviour to infer the user's learning progress and to dynamically adapt presentations of topics and links accordingly.     

An Experiment on the Integration of Hypertext within a Multi-User Text Retrieval System

Currently, few hypertext systems allow an author to incorporate electronic textual information into a hyperdocument without first copying it from the environment in which it is stored. In order to extend a hyperdocument, an author must either manually type in the new information or import a copy of the text. To avoid this inconvenience and thus improve the user's efficiency of operation, hypertext systems must be integrated into other environments so that an author can incorporate existing text into a hyperdocument without the necessity of duplicating the text. This paper presents the results of an investigation into how hypertext could be integrated within a multi user text retrieval system and describes the design and implementation of a prototype system called Hyperbrowser.     

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.     

Interactive visualization of dependencies

We present an interactive tool for browsing course requisites as a case study of dependency visualization. This tool uses multiple interactive visualizations to allow the user to explore the dependencies between courses. A usability study revealed that the proposed browser provides significant advantages over traditional methods, in terms of learnability, efficiency and user confidence. The results are discussed within a general framework for interactive visualization of dependencies.     

Effectiveness of Information Retrieval Systems Used in a Hypertext Environment

In most hypertext systems, information retrieval techniques emphasize browsing or navigational methods which, unfortunately, are not thorough enough to find all relevant material, especially when the number of nodes and/or links becomes very large. This paper reviews briefly the main query-based search techniques currently used in hypertext environments. Next, after explaining our own experimental methodology, this study concentrates on the retrieval effectiveness of these retrieval strategies. Based on our results, some discussion points are clarified and some interesting avenues for improving search effectiveness are promoted.     

Phone‐Web: Accessing WWW using a telephone set

In order to provide a ubiquitous, comprehensive and versatile service on the WWW the development of a WWW telephone browsing system named Phone‐Web is proposed. This Phone‐Web browser system would act as an intermediary between the telephone user and Web sites, thereby facilitating access to the WWW from any phone. The Phone‐Web system would filter Web page information and then convert it into speech format. Users of the Phone‐Web system could retrieve and hear information stored on WWW servers by using telephone handsets. For this system to work it requires a new hypertext language “Hyper Phone Markup Language” (HPML) and a dedicated Phone‐Web browser. By using the proposed HPML language, Web page designers can easily specify service information in a set of HPML pages, which would be included in the site they are designing. The Phone‐Web browser would be capable of retrieving and then converting the HPML pages into speech patterns. By connecting to the Phone‐Web browser, telephone users can access any information on any site using the HPML language from any telephone anywhere in the world. However, HPML‐specified pages can also be accessed using existing browsers (e.g., Netscape Navigator, Microsoft Internet Explorer, etc.) This means that both telephone and computer users can now access the same set of Web pages to retrieve the same information. Therefore, instead of maintaining the existing two systems (access via the telephone or computer) service providers can now maintain one system, which would provide a versatile, and comprehensive service for users at all levels of Web‐literacy. This revised version was published online in August 2006 with corrections to the Cover Date.