CHAPTER 1 : HOW DID WE GET HERE?

Introduction

The origins of hypertext can be traced back through some considerable length of time – for example, in his often-cited introductory article, Conklin (1987) makes passing reference to the Talmud and the work of Aristotle, and in the past there was certainly an appreciation of the inter-connectedness of information. If this is the case, why has hypertext suddenly become the focus of so much attention?

In fact, like most ‘overnight’ successes, hypertext hasn’t suddenly arrived. Several research groups in academic institutions and industrial concerns have been developing and using hypertext systems since the 1960s. What has developed rapidly in recent years is the ready availability of an enabling technology – the computer. While it is certainly true that the ideas underlying hypertext have been around for many years, it is the vastly increased availability of computing power that has allowed the implementation, elaboration and exploration of these ideas.

As recently as 1964, the computing effort of the entire British academic community was handled by a single Ferranti Atlas machine housed in the Science and Engineering Research Council’s Rutherford Appleton Laboratory. These days, all academics have ready access to mainframe computers and many also make extensive use of minicomputers and personal microcomputers. Hypertext has made the same journey, from mainframe to micro, and in the process has gone from academic research area to commercial software venture. Hypertext packages are

now potentially ‘big business’ and consequently forces other than research results or practical experience are being exerted on the field.

In this book we will explore the tripartite themes of people using computer-based information to perform a task in what has come to be known as a hypertext (or, more generally, hypermedia) environment. At times we may focus on one aspect at the expense of the other two, but it should be remembered that a proper consideration of hypertext necessarily involves all three.

It is perhaps a fitting irony that the best way to disseminate our views is via the paper-based medium of a book. In 1982, Jonassen predicted that "in ten years or so the book as we know it will be as obsolete as is movable type today" (Jonassen, 1982, p.379) – a sentiment which apparently echoed the feeling of the pioneer Ted Nelson 20 years earlier, although in a lecture delivered in 1989 Nelson said he had thought books would be a thing of the past within five years, that is, by 1967 (Nelson, 1989). From our point of view, books will be a feature of information dissemination for many years to come. In this book, therefore, the relevant question will not be "when will hypertext replace books?" but rather "when is it better to present the information via hypertext rather than via paper?" When we talk about hypertext, we are talking about people using information to perform a task. and hence we will be concerned to elucidate the nature of the tasks which are best supported by the medium.

What is hypertext?

What, then, are the ideas which have become the centre of a vast research effort and the subject of several large academic conferences in recent years? Simply stated, hypertext consists of nodes (or ‘chunks’) of information and links between them. Stated thus, it is easy to find early examples of hypertext – any text which references another can be seen as two nodes of information with the reference forming the link; any text which uses footnotes can be seen as containing nodes of information (the text and the footnote), with the footnote marker providing the link or pointer from one node to the other. As we shall see later, the idea of a node is very general, and there are no ‘rules’ about how big a node should be or what it should contain. Similarly, there are no rules governing what gets linked to what.

What makes hypertext different, what sets it apart from the most conceptually inter-linked paper document, is that in hypertext the links are ‘machine-supported’. When the reader selects a hypertext link, the ‘movement’ between the two nodes takes place automatically. It is for this reason that the advent of hypertext has had to wait for the combination of processing power and display embodied in the modern computer.

For example, the screen shown in Figure 1 displays a hypertext concerning music. The ‘top’ level (obscured in this view by overlapping windows) offers the user a view of music organised by instrument, composer, historical time-line or geographical location. In this case, ‘composer’ has been chosen, and the composer Wolfgang Amadeus Mozart has been further chosen for investigation. From here the user can access films about Mozart, display and print out musical scores, listen to complete works, read a biography and so forth. Of course, all these are interlinked so that from listening to music it is possible to move to the score and vice versa. In the biography, when a particular piece of music is mentioned, selecting the (bold) text plays an extract of the piece. When the text says that Mozart was born in Salzburg, a map can be called up showing Austria and surrounding countries and marked with the birthplaces of other composers, any of which could then be selected. All this movement around the information is achieved by the user or reader selecting items on screen with a mouse or other pointing device. What previously would have entailed visits to various libraries, sound libraries and cinemas can now be achieved from the desktop.

This example serves to show how flexible the concepts of node and link are. A node of information can be a fragment of music, a piece of text, a map, a complete film – anything which the author thinks can sensibly be presented as a unit. Even if a particular hypertext system always displays one screenful of information at a time, a node can consist of several consecutive screens. Similarly, a link is arbitrary in the sense that there are no rules to say where a link shall be made. A link can be made between any two nodes which the author (or often the ‘reader’ as we shall see later) considers to be connected in some way. In some systems, the links are ‘typed’, i.e., there are several types of link and the author must specify which type he would like to make at any one time. For example, the system might limit links to those which connect information offering support for an argument, refutation of an argument, an example and so forth. However, many systems use untyped links. As we shall see in the chapter on authoring, the flexibility of the size of nodes and the positioning of links places a burden on the author and reader which many paper documents do not.

Various hypertext systems have implemented the simple ideas in different ways and hence superficially they might look quite different. They might even feel

different to use. For example, selecting a link may cause an overlapping window containing the linked text to open, or it may replace the node with the linked node. Similarly, replacing a node with a linked node may be couched in terms of ‘unfolding’ or of physical jumping between nodes. However, there is sufficient similarity between the different systems to allow their grouping under the heading of ‘non-linear text’, ‘dynamic documentation’, or hypertext.

The fact that links are supported electronically is insufficient to define a system as hypertext. For example, database management systems (DBMSs) have links of various kinds, notably relational and object-oriented links. It might be possible to build a free-form relational database resembling a hypertext database, but such systems usually emphasise ‘selection against criteria’ and ‘reporting’ rather than reading and browsing.

Similarly, the inverted file common in information management systems (IMSs) could be seen as a set of links allowing any word to be accessed. However, in such systems a word is simply an alphanumeric string, the basis for a search operation rather than a unit of meaning. A sophisticated system will allow the user (or, more typically, the ‘database administrator’) to define synonyms in terms of links between equivalent terms in the inverted file, and a thesaurus of words and phrases arranged according to their meaning could be constructed with the inverted file terms as the base level. However, the operation is still essentially one of searching rather than linking on the basis of meaning.

With both the DBMS and the IMS it is possible to build a database which ostensibly resembles hypertext, so why are such constructions not really hypertext? What differs is the underlying purpose for which such systems were designed, and consequently the effort involved in producing such a database and supporting changes to it. The situation is analogous to a graphics package with a text facility; such a package could be used to produce a paper document indistinguishable from the output of a word processing package, but the effort required is related to the purpose for which the package was designed. You could write letters with a drawing package, but you wouldn’t.

Why is hypertext important?

There are many developments taking place in research laboratories each year, so why should hypertext be seen as important enough to merit the attention it is receiving? Its importance is based on the fact that it offers a very powerful way of organising and accessing information and hence has a potential rôle to play in the development of information technology, which in turn is shaping the society in which we live. If we look at the period from 1961 to 1981, there was a strong growth in both information occupations and information industries. The greatest growth was exhibited by information occupations in information industries, followed by non-information occupations in information industries, followed by information occupations in non-information industries. The fourth group, non-information occupations in non-information industries, experienced a consistent and accelerating decrease in percentage of job opportunities over this period. Projections of future employment made on the basis of these trends show a continuing move away from manufacturing industry towards services, especially services with an information content (Angell, 1987).

An increase in information work, coupled with an increased use of communication technology, could lead to wide-ranging changes in society. Following the Industrial Revolution, many towns developed around sources of power such as coal mines and rivers. With more people able to work remote from an office, there is a decreasing need for populations to build up in towns. As demographic factors such as dwelling patterns change, so too does the nature of society. Patterns of interaction change and the style of life changes. These changes permeate through society affecting, for example, the kinds of crime committed. Computer-related crimes are now commonplace, ranging from large-scale fraud to ‘hacking’ of Prince Philip’s electronic mail.

Hypertext’s importance resides in the fact that it may alter the way in which we read, write and organise information. As we will suggest in Chapter 2, these skills have supported the technical advances of the last 3000 years. Any powerful information access and retrieval mechanism will have potentially wide-ranging effects, and these will extend beyond the office into the school and even the home.

Of course, some of the claims made for hypertext need careful consideration. For example, it has been claimed that hypertext will change the way we think. In a modified version of such a claim, Beeman et al. (1987) suggest that education is about the development of "non-lineal" thinking and that hypertext assists in the development of this style of thinking. We will consider the rôle which hypertext can play in education in Chapter 6. Marchionini and Shneiderman (1988) echo this view when they say that "the application of computers as cognitive augmenting agents will improve cognitive performance and change the way we think." For these authors, hypertext systems are "the next generation of word processing" which will change the way people read and write. Any such claims must of course be subjected to experimental testing, and we will review many experimental findings in later chapters.

Hypertext historical highlights

Rather than indulge in historical oneupmanship – who knows, maybe the scratchings around the cave paintings were the first primitive hypertext links? – we will begin our brief overview of the history of hypertext in the same era as the birth of the technology which supports it. The article most often cited as the birthplace of hypertext is Vannevar Bush’s "As we may think" (Bush, 1945). The link between hypertext and thought implied in the title of Bush’s article is an interesting question which we will address in more detail in Chapter 6.

Bush was appointed the first director of America’s Office of Scientific Research and Development by President Roosevelt in 1941. He saw clearly the problems associated with ever-increasing volumes of information:

Presented with an extract such as this, it surprises many people to discover that the author was writing 45 years ago, since many contemporary writers have made exactly the same point about the ‘information explosion’.

To cope with this plethora of information, Bush designed (conceptually, at least) the ‘memex’, a device "in which an individual stores his books, records, and communications, and which is mechanized so that it may be consulted with exceeding speed and flexibility." More than a simple repository, the memex was based on "associative indexing, the basic idea of which is a provision whereby any item may be caused at will to select immediately and automatically another. This is the essential feature of the memex. The process of tying two items together is the important thing."

For Bush, ‘tying two items together’ was important because it seemed to him to follow the workings of the mind, which

In view of the way we described the essential features of hypertext earlier, it is not difficult to see why Bush is often regarded as its founding father.

In conception, the memex was a remarkable ‘scholar’s workstation’ and Bush thought that it would allow a new form of publishing, with documents "ready-made with a mesh of associative trails running through them, ready to be dropped into the memex and there amplified." Unfortunately for a visionary like Bush, the technology of the day was not up to the task of instantiating the memex. He assumed that microfilm would cope with the bulk of the storage problem, which might have been true. However, the level and complexity of indexing and retrieval required by the memex was certainly beyond microfilm-based technology. The memex was a problem in search of a solution, and the solution was the computer.

The one thing which Bush did not do was to name this nascent field of endeavour. The term ‘hypertext’ is attributed to Theodor (Ted) Nelson, a character who 25 years after coining the term can still hold an audience’s attention with his vision of how the future of literature might look. Nelson’s Xanadu project – characteristically named after the site of Kubla Khan’s pleasure dome in Coleridge’s poem – is aimed at the creation of a ‘docuverse’, a structure in which the entire literature of the world is linked, a "universal instantaneous hypertext publishing network" (Nelson, 1988).

In Xanadu, nothing ever needs to be written twice. A document is built up of original (or ‘native’) bytes and bytes which are ‘inclusions’ from other documents in which they are themselves native. By the Summer of 1989, Nelson had moved from speaking of ‘inclusions’ to speaking of ‘transclusions’, a term which implies the transfer and inclusion of part of one document into another. However, an important aspect of Xanadu is that the transclusion is virtual, with each document containing links to the original document rather than copies of its parts.

It could be argued that someone who speaks of a docuverse, xanalogical structure and transclusions should not be surprised that his project is "not well understood." However, Nelson continues to work towards his vision, publishing details of the ‘humber’ system for keeping track of the large number of documents in the docuverse (Nelson, 1988) and distributing flysheets announcing the imminent availability of the Xanadu Hypermedia Information Server software.

Although Nelson is seen as one of the gurus or Grand Old Men of hypertext, the idea of much of the world’s literature being connected had been suggested many years previous. At a talk given in 1936 (and subsequently published in 1938), almost ten years before even Bush’s article, the British writer and visionary H G Wells had described his idea of a World Encyclopædia, the organisation of which would:

In a world which was about to be embroiled in the greatest war ever, Wells’s article can be seen as a plea for thinking people to work together in peace. Modern political theorists might now judge the article to be naïve, but the practicalities – including issues like copyright which Wells foresaw – are still being worked on today in the field of hypertext.

Nelson may have given hypertext its name but he was by no means the only person working on the ideas. Although perhaps better known as the inventor of the mouse pointing device and the five-key ‘chording’ keyboard, Doug Engelbart has been pursuing his vision of hypertext since the early 1960s. Engelbart’s emphasis has always been on augmenting or amplifying human intellect, a fact now reflected in the naming of his system as Augment. His original proposal was for a system he called H-LAM/T – Human using Language, Artifacts and Methodology, in which he is Trained – although the first implementation had the simpler title of NLS – oN Line System. NLS was meant as an environment to serve the working needs of Engelbart’s Augmented Human Intellect Research Centre at Stanford Research Institute, a computer-based environment containing all the documents, memos, notes, reports and so forth but also supporting planning, debugging and communication. As such, NLS can be seen as one of the earliest attempts to provide a hypertext environment in which computer-supported collaborative work could take place, a development which will be discussed in more detail in Chapter 8.

We can see Bush, Nelson and Engelbart as representing three different views of hypertext which continue to attract adherents today. The Bush view sees hypertext as somehow ‘natural’, reflecting the mind or (in the strongest form of this position) modeling the mind; from this perspective, hypertext should feel easy to use. The Engelbart view of hypertext is as an augmentation environment; the user of hypertext should be able to achieve more than would be possible without it. Although Nelson’s vision is perhaps the most ambitious, his view of hypertext is as a storage and access mechanism; the user of hypertext should be able to access any document, and such ease of access should work to break down subject boundaries.

These views are not mutually exclusive; it is possible to advocate a hypertext system which provides ready access to all information and therefore allows users to perform new tasks. Indeed, there is a fine line between these idealised positions and it is not always possible to describe any particular system (or system designer’s viewpoint) in terms of one or any of them. However, the fact that different views can proliferate illustrates the point that ‘hypertext’ is not a unitary concept, not a single thing which can be defined any more precisely than in terms of nodes and links. It is for this reason that hypertext software packages with completely different ‘look and feel’ can be produced and still claim to embody the concept of hypertext.

Although many hypertext systems have been developed since the pioneering work of Nelson and Engelbart, it is not our intention to describe them all in this chapter. Conklin (1987) lists 18 systems and his list is not complete if for no other reason than because others have been developed since his article was written. Rather, we will now move to the end of the chain leading from mainframe to microcomputer and mention only two other people who seem to us to be important for various reasons.

Randall Trigg is credited with the first PhD thesis on hypertext (Trigg, 1983) in which he describes a system called Textnet. However, Trigg has had a greater impact on the field of hypertext since he moved to the Xerox Palo Alto Research Centre where he was one of the developers of the NoteCards system (Halasz, Moran and Trigg, 1987). NoteCards was designed as an information analyst’s support tool, one which would aid the analyst in forming better conceptual models and analyses. As its name suggests, the system implements in electronic form the well-known index or note card much used by information workers, and extends the metaphor to include the FileBox (traditionally a shoe-box).

The main factor which has limited the use of NoteCards is that it requires the use of an expensive Xerox Lisp computer. Even so, it has been used as a research tool in several application areas, with Trigg also exploring its use as an environment in which to perform computer supported collaborative working (Trigg and Suchman, 1989). However, possibly the biggest impact which NoteCards has had has been indirect; like several other aspects of the work at Xerox PARC, it has influenced Apple Computer and can be seen as the model for Apple’s HyperCard. Today HyperCard is the most widely distributed hypertext system and consequently the best known and most used.

Unfortunately, while HyperCard has served to introduce the word hypertext into many peoples’ vocabulary, it has also been responsible for giving many of these people a wrong impression. HyperCard is a powerful tool, one which can do more than produce hypertext documents. It has an important use as a rapid prototyping tool and even an application generator – it has been called ‘the programming environment for the rest of us’ echoing Steve Jobs’ description of the Macintosh as ‘the computer for the rest of us.’ Hence, some people have assumed that the context of hypertext is sufficiently all-embracing as to include such things as the fully functional mobile phone simulation built in HyperCard by some of the authors’ colleagues at the HUSAT Research Institute. It is a mistake to think that everything produced using HyperCard is hypertext or, conversely, that all hypertext systems have the same properties as HyperCard.

The movement from research laboratory to commercial software venture is one which has not been made very often. However, the Guide hypertext system currently available commercially for the Apple Macintosh and IBM PC, can claim to have made the transition with some success. The system has been the subject of research and development by Peter Brown and colleagues at the University of Kent since 1982, but in 1984 Office Workstations Ltd (OWL) became interested and have since developed the microcomputer versions. The original system, still the focus of research at Kent, runs under the Unix operating system.

Unlike many systems which use the card metaphor or present information a screen at a time (like pages), Guide uses a scrolling method similar to word processors. Indeed, a Guide document is presented as a single scrolling field. Within the text are ‘buttons’ which, when selected, are replaced by the associated text. For example, Figure 2 shows a screen from a journal article held in Guide format; when the word ‘Introduction’ is selected, the text is unfolded from behind the button as in Figure 3. Clicking on the text causes it to be re-folded behind the button. A read-only version of Guide has been used to distribute at least two books to date: the proceedings of the First UK Hypertext conference (McAleese, 1989b) and Ted Nelson’s Literary Machines. To the best of our knowledge, the book which has only been distributed in hypertext form has yet to arrive. However, the concept of hyperfiction has been discussed (Howell, 1990), and short stories have been distributed in hypertext format (e.g., Engst’s (1989) Descent into the Maelstrom), so it may be only a matter of time before an original hyperbook appears.

Many more hypertext systems exist and will continue to be developed in various centres around the world, including the USSR where the Hyperlog system has been developed. Several of them will be mentioned in ensuing chapters, with the glossary containing brief details of the more important systems mentioned and a reference to an original source if further information is required. Our aim in the present chapter was not to list all known systems but rather to indicate the different viewpoints which have led to the development of very different systems under the umbrella of hypertext.

Overview of the book

In Chapter 2, we suggest that the significance of hypertext can only be assessed by way of an appreciation of the historical development of text systems. We feel that this perspective clearly reveals some popular conceptions concerning the linearity of traditional text structures to be largely misconceived, and this in turn brings into question some of the alleged advantages claimed for hypertext.

Text systems have evolved considerably in terms of physical technology – from papyrus to photo-typesetting – but this change is modest compared to the change in our attitudes towards the rôle of writing. The evolution of the technology and the cognitive skills of the users can be seen to be closely related to the the usage of writing. Current hypertext systems do not appear to be capitalising on these hard-won skills.

Hypertext is not simply better or worse than paper documentation but it is different. In Chapter 3 we discuss the usability of hypertext by examining the users, their tasks and the texts from a psychological viewpoint. Drawing on the literature from psychology and ergonomics we demonstrate that in order to design a good hypertext system we need to address the interaction of the three elements of user, task and text.

To some people, navigation is the single biggest problem in hypertext, while others deny that such a problem exists. In Chapter 4 we address directly the problems of navigating through a complex information space. We review empirical evidence for the existence of the ‘navigation problem’ and, by drawing on psychological theories of navigation in physical environments, suggest how it might be lessened in the electronic domain.

The successful introduction of hypertext as a commonplace medium for organizing and accessing information will require the resolution of a number of practical and conceptual problems (in addition to the inevitable problems of standardisation and compatibility/interoperability). Many of the practical problems associated with creating hypertexts will prove to be less important as the transition to electronic information exchange progresses but the conceptual problems are less susceptible to technical solutions.

While the book as a medium has managed to support both searching and extended browsing successfully for some 500 years, this facility has declined as text length has increased. Contemporary technical texts may run to millions of pages and print is no longer a viable medium but although today’s hypertext systems offer effective searching facilities, their support for browsing is often poor. Part of the problem results from the adoption of radical document architectures which place more emphasis on the computer’s ability to support them than on the reader’s ability to understand or make use of them. Traditional text structures are closely interrelated with our conceptions of intellectual argument and understanding of knowledge. Relatively unstructured hypertext networks would seem to be an inappropriate form for advanced teaching or learning but may prove a valuable tool for exploring and organizing information. We explore these issues in Chapter 5.

One of the areas in which hypertext might have far-reaching implications is that of education. Various claims have been made for the effectiveness of hypertext as a learning environment, and these claims are examined at length in Chapter 6 in the context of the educational process in general and the rôle of microcomputers in particular.

In Chapter 7 we describe the development of a hypertext database which embodies the design philosophy outlined in earlier chapters. The initial specification work and design decisions are outlined and users’ responses to the interface are described.

Finally in Chapter 8 we outline the areas in which we think the future of hypertext lies and the areas to which research could be fruitfully directed.