Hypertext: The New Way of Browsing

• Autore: Roy Rada
• Pagine: 33-46

Page 33

@1. History

Vannevar Bush was a Director of the Office of Scientific Research and Development and was involved in coordinating the activities of some six thousand American scientists in the application of science to warfare. Towards the end of the Second World War he perceived a problem to which the emerging technology of computing might provide a solution. He articulated the problem thus [Nyce Kahn 1989]:

There is a growing mountain of research, But there is increased evidence that we are being bogged down today as specialization extends. The investigator is staggered by the findings and conclusions of thousands of other workers - conclusions which we cannot find time to grasp, much less to remember, as they appear.

Bush proposed a technological solution to this problem in the shape cf a device he termed the Memex. (Memory Extender). This was a device in which an individual stores all his items of information in miniaturize form and which allows for their subsequent consultation and processing with great speed and flexibility.

However, it was not so much the technology that was important about the Memex but what this technology made possible. The all important feature ot the Memex would be its provision for associative indexing ´...whereby any item may be caused at will to select immediately and automatically anotherª. Significantly, perhaps, asscociative indexing would be provided, in addition to a conventional scheme of indexing. Perhaps Bush's most important insight was that in order to cope with and benefit from the vast production of information it was not merely sufficient to augment mankind's capacity for logical thought. The only way that mankind could benefit from having so much informatics to hand was through the amplification of his faculty for creative thought.

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Since 1945 Bush's ideas have inspired a growing number of researchers. ´As We May Thinkª is considered a seminal article in the field of hypertext and also, latterly, in the important field of computer-supported cooperative work. In 1981 it was noted that in the years since the publication of the article it was still being cited as a major point of reference in a growing number of papers in information science. It must be assumed that this process has continued, since the 1980s saw the emergence of popular commercial hypertext. Such is the extent of Bush's influence that it has been suggested that Bush's Memex has provided an image of potentiality. Images of potentiality result when untested theories, unanswered questions, or inbuilt devices guide scientists and technologists. Bush neither tested his theory of associative indexing nor built Memex but his ideas have influenced the work of many others.

The inter-connectedness of information is surely not an idea of this century. It was conceived thousands of years ago by those who started thinking philosophically. However, this idea has become the origin of hypertext, as hypertext is considered a set of nodes of information connected with links between them. The importance of hypertext is based on its potential to be a very powerful way of organizing and accessing information. The vastly increased availability of computing power has allowed the implementation, elaboration and exploration of the ideas underlying hypertext. [McKnight context 1991]

The idea of a node in hypertext is one without certain restrictions about its dimensions or content. A node of information can be a piece of text, a piece of music, a film, etc. There is also no restriction about the nodes that are going to be linked together. Therefore, a link is arbitrary as there are no rules to say where it shall be made. The author makes links between any two nodes he thinks that are connected in some way. There can be several different types of links in some systems. The difference between hypertext and an inter-linked paper document is that in the former the links are ´machine-supportedª, This allows automatic transfer between two nodes, when a hypertext link is selected. For this to happen there should be the proper computer technology developed and therefore hypertext had not appeared until recently (1964).

@2. Accessing Hypertext

Accessing information entails both quantitative and qualitative aspects.

The computer can scan huge volumes of text for a pre-specified pattern of characters far more efficiently than the unaided human. But until recentlyPage 35 computers were not capable of allowing users to browse large volumes of information for a number of reasons:

* The high cost of computing time and communciations links made it uneconomic to allow users to take the time to browse.

* The techniques of human-computer interface design had not been developed that would encourage browsing.

* Computers had not entered domains where browsing is an iImportant activity.

Now, however, there is a vast amount of information that can only be accessed via a computer with a telecommunication's link to the international networks. This makes it essential that users have the opportunity to browse this Information, for it is by browsing that one builds a conceptual picture of domains of knowledge.

Traditionally, computer-based Information retrieval systems have not been designed to allow browsing. This is partly due to the nature of the Information stored, that is, mainly small, compact items of data amenable to storage in fixed-length records; and also partly due to the requirements of users, These systems have been designed to allow users to find Information on demand, and require that the users approach the system with a clearly defined Idea of exactly what they want, Howwer, full text and multimedia systems need to be designed so as to allow the users to browse.

The browse process depends fundamentally on Information being organized systematically according to a consistent model. This organization should allow the user to navigate, or browse, at will. Hence, the importance of domain modeling In the design of information-systems. Domain modeling aims to provide a framework for the identification of objects, operations, and other structures that can be captured as concepts. It achieves this through detailed analysis of a domain corpus of existing Items. Ideally, both domain expertise and expertise in general domain modeling are needed for the efficient performance of this task.

Hypertext is often associated with browsing as the access strategy. A dictionary definition of browse is ´to read desultorilyª, and ´desultorilyª is defined as ´jumping from one thing to another: without rational or...