3.3.6. Use of hypertext in CASE tools Introduction

Hypertext and multimedia are emerging technologies in information systems development. The justification for the use of hypertext is judged by two main principles of hypertext itself. On the one hand it is a 'technology' that is able to combine many kinds of media, providing a basis for multimedia. On the other hand, with hypertext it is possible to provide to every user just the information he needs, and even in the way he prefers. Goal

Our aim was to examine how information systems descriptions can be effectively utilised and represented in a user-friendly manner using hypertext as an integral part of the CASE environment. We also aimed to examine how such technologies can improve co-operation support between the systems developers. Contributions

Fundamentally the research is based on the concept of an 'intermediary hypertext agent' developed by Kerola and Oinas-Kukkonen (1992). The four main areas of how CASE tool components and their routine use can be empowered with hypertext were recognised in (Oinas-Kukkonen, 1992) as support for the user interface, document integration, the representation of semi-structured information, and collaboration. A prototype hypertext application was implemented with ToolBook for Windows for both methodology and CASE tool tutoring, training and use (Oinas-Kukkonen, 1994a, 1994b). The preliminary findings were presented in (Oinas-Kukkonen, 1993a). We found out that a monolithic hypertext application did not support sufficiently the real application of the methodology using the CASE tool. Therefore a new approach was needed to incorporate the desired hypertext functionality into "non-hypertext" information systems, i.e. the information system is provided with additional support features with hypertext functionality (Oinas-Kukkonen,1993b).

The preliminary findings also led us to focus on user-related adaptability as a key feature when studying hypertext in CASE environments. The general research question since then has been: How can one support user-related adaptability in CASE environments with hypertext functionality? Adaptability is characterised as a quality factor for an information system. The key aspect to achieve user-related adaptability is to provide support for the representation of semi-structured information, in particular in the early phases of the development process, when the degree of formalisation is by definition much lower than in the later phases of the development.

The two main (yet unpublished) contributions on hypertext in the latter part of the project can be summarised as:

the recognition and definition of the new functionality approach, and

the development of the prototype of the hypertext functionality in MetaEdit+. Constructive work

The prototype of the hypertext functionality in MetaEdit+, called the Linking Ability, supports the basic MetaEdit+ tools, namely Draw Window, MatrixEditor and Repository Browser, by providing an alternative way to navigate in the collection of design documents based on a user's associations. See Figure 2. However, the user of the MetaEdit+ will not necessarily even recognise that he has used the Linking Ability, since he will access all the link information via the normal user interface (the Workspace).

Accordingly, MetaEdit+ users are not required to create any links or nodes in their design documents if they do not want to do so. The user can also connect the existing documents or parts of them by links, without ever creating new nodes. Therefore, the concept of a link was adopted as the basis for developing the Linking Ability prototype. However, creating annotations and capturing the design rationale is also enabled in the prototype.

A new link taxonomy has been developed (eight kinds of links) with facilities to store and query information via link attributes, link typing, and the attachment of keywords. The basic kinds of links are: association, note, and bookmark. An association link connects two design documents or regions of them. Via note links annotations can be attached to the documentation. A bookmark link provides the tool user with an aid to remember to return to a specific point in the documentation. Special kinds of association links can be used to connect the deliverables of the different phases to the development process. With special kinds of annotations, debate components, the support for design rationale can be established. By supporting the capturing of design rationale and the process modelling, Linking Ability is in tie with the Agent and Activity (i.e. process) models. Landmark and other signs provide specialisations for bookmark. We also provide links to documents created by other applications. In addition to the selection of the links, navigation is supported by composite link structures and link lists. A similar kind of linking functionality is provided for text components, such as annotations, by the use of hotwords. Future work

In the future the prototype will be further developed and a descriptive framework will be constructed for the development of the hypertext functionality in CASE tools (or in information systems in general) (Oinas-Kukkonen, 1993b). Reviews and a laboratory test on the use of the hypertext functionality prototype are being planned.