The electronic business card: an experiment in half-dead hypertext

Abstract

Half-dead hypertext has links where the user has to do some work to retrieve the destination nodes (for example mount a CD-ROM or send an email message). Also, response times may be so slow that users do not have the normal hypertext feeling of freely navigating an information space. This is in contrast to normal live hypertext where the nodes appear immediately upon activation of a link anchor and dead hypertext where the links are simple cross-references to material that is not available on the computer and thus cannot be retrieved at all. Half-dead hypertext can be used in cases where live links are technically difficult or impossible to support. One example is the electronic business card, which is a link to further information about its owner. Electronic business cards can be transmitted between personal digital assistants and will allow the recipient to link to much more extensive information than can be transmitted and stored on a PDA platform. Also, electronic business card links can be printed in brochures, research papers, and other non-electronic media from which access to the server can be made with human intervention.     

Using XML for Supplemental Hypertext Support

Our overall research goal is providing hypertext functionality through the WWW to hypertext-unaware information systems with minimal or no changes to the information systems. Information systems dynamically generate their contents and thus require some mapping mechanism to automatically map the generated contents to hypertext constructs (nodes, links, and link markers) instead of hypertext links being hard-coded over static contents. No systematic approach exists, however, for building mapping routines to create useful links that give users direct access to the ISs' primary functionality, give access to metainformation about IS objects, and enable annotation and ad hoc (user-declared) linking. This paper contributes a procedure for analyzing ISs and building mapping routines that supplement information systems with hypertext support. This paper also contributes an eXtensible Markup Language (XML) DTD that declares a set of elements and attributes for representing mapped information in a human-readable, machine-readable, structured, and semantic way. We implemented a prototype to demonstrate the feasibility of using XML to represent mapped information.     

Broadbutton Node Linking — A Generalised Approach to Hyperbase Navigation

Hypertext systems operate by establishing links within information, Links are normally established by an author, although some systems — GUIDE, for example — make little distinction between author and user, permitting deliberate modification of existing connections. However, linking between nodes, whether by original author or later user, is typically an active process. Producing effective hypertext links involves knowledge both of the system and of the particular data set within it.

I suggest that efficient link building might be greatly facilitated, and existing systems given greater functionality, if two related modifications could be made. Firstly, more general or ‘broad-button’ nodal links could be created; I use the phrase ‘broad button’ linking to describe ranked connections established between areas of a hyperbase. The term is defined in detail below. Intended to be easily selectable, broad-button links would offer users the choice of a ranked list of destinations from any point within any node. Secondly, were nodes to be ranked in order of probable user choice, allowing users a degree of feedback following selection of a node would permit such ranking to be dynamically organised. Feedback of this kind also has potential in assisting automatic establishment of appropriate new links between nodes.

In this paper I describe how such modifications might be organised, and describe some experiments which are currently being planned and undertaken to evaluate the ‘broad-button linking’ process.     

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.     

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.     

Spatial metaphors and disorientation in hypertext browsing

Abstract

The spatial metaphor can be used as a framework for explaining and designing tools that alleviate disorientation problems in hypertext systems. The approach based on this metaphor would involve developing tools analogous to navigational aids in physical environments and applying analogous concepts from research on human spatial processing and navigation in physical spaces. Research on hypertext browsing with respect to the spatial metaphor is reviewed and contrasted with the larger task context where users are trying to explore, learn, analyse, and summarize the contents of the hypertext space.     

GOHSE: Ontology driven linking of biology resources

We describe the GOHSE system, an application to support browsing of biology resources. The Conceptual Open Hypermedia Service (COHSE) system enhances web resources through the dynamic addition of hypertext links. These links are derived through the use of an ontology and associated lexicon along with a mapping from concepts to possible link targets. GOHSE applies COHSE to Bioinformatics, using the Gene Ontology (GO) as an ontology and associated keyword mappings and GO associations as link targets. The resulting demonstrator provides both glossary functionality and the possibility of building knowledge based hypertext structures linking bioinformatics resources.     

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.     

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.     

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.     

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.     

Effect of high-level content organizers on hypertext learning

This study investigates the cognitive abilities involved in hypertext learning and design approaches that can help users. We examined the effects of two types of high-level content organizers - a graphic spatial map and an alphabetical list - on readers’ memory for hypertext structure. In the control condition, a simple “home” page with no navigational aid was offered. Subjects were asked to read the hypertext with the purpose of learning the content, but in the post test phase they also had to recall the layout of nodes and links. Memory for links and page places varied as a function of condition. When a spatial map was available participants reconstructed more accurate formal structure then in the two other conditions. Participants’ memory about page places was the least accurate in the list condition. Results also indicate that participants use the content organizer when it is available in order to orientate during learning from hypertext documents.Our results prove that a content organizer showing the formal structure can facilitate the spatial mapping process. However, an organizer exposing a different structure than the real one would generate a conflict.     

Proficiency-Adapted Information Browsing and Filtering in Hypermedia Educational Systems

We present a framework for proficiency-adapted information browsing and filtering in educational hypermedia systems. In hyperdocuments, information is acquired by browsing through highly interconnected sets of information nodes. In order to find specific information, users follow links to nodes they judge to be relevant. In order to help users find relevant information and new learning material that match their levels of domain knowledge, we present a framework for adapting the information nodes, and the links leading to them, to the user's proficiency in the subject matter. Such a proficiency-adapted, user-centered educational environment is intended to enhance learning. We believe that learning in educational hypertext-based applications cannot be reduced to traversing a static information space. Navigating through any space, be it a physical or an information space, normally requires that users have a prior degree of proficiency in the domain knowledge. Learning is an evolving dynamic process through which users progress from a situation of unfamiliarity to one of mastery of a knowledge corpus. Therefore, we propose a model of proficiency-adapted learning and information browsing in which the presented choices (links and the textual context of links) are selected based on the user's knowledge state. Ultimately, such an adaptive course not only guides the learning process of the student, but it gradually transforms itself into a reference guide. This revised version was published online in July 2006 with corrections to the Cover Date.     

Cognitive load in hypertext reading: A review

A process model of hypertext reading was used to generate predictions about the effects of hypertext features on cognitive processing during text navigation and comprehension. We evaluated the predictions of the model with respect to the extant literature, focusing on studies in which versions of hypertexts were compared. Consistent with our predictions, the increased demands of decision-making and visual processing in hypertext impaired reading performance. Individual differences in readers, such as working memory capacity and prior knowledge, mediated the impact of hypertext features. For example, readers with low working memory and low prior knowledge were usually disadvantaged in hypertext. Some benefits were observed for learners with low prior knowledge, however, if the hypertext structure was hierarchical and consistent with that of the knowledge domain. We also surveyed the effectiveness of structural features designed to reduce cognitive load, including graphical overviews, restricted access to links, and visible link types. Complex graphical overviews did not reliably enable learning and navigation, whereas navigational support from restricted access and visible link types were helpful. We identified gaps in the empirical literature and suggested future studies to investigate cognitive processes in hypertext reading.     

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.     

Spatial metaphors and disorientation in hypertext browsing

The spatial metaphor can be used as a framework for explaining and designing tools that alleviate disorientation problems in hypertext systems. The approach based on this metaphor would involve developing tools analogous to navigational aids in physical environments and applying analogous concepts from research on human spatial processing and navigation in physical spaces. Research on hypertext browsing with respect to the spatial metaphor is reviewed and contrasted with the larger task context where users are trying to explore, learn, analyse, and summarize the contents of the hypertext space.     

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.     

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.     

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.