|Table of Contents|
|Table of Contents|
Storage and presentation of modules has to be sufficiently standardised to allow the reader to locate, retrieve and consult modules written by different authors in a similar fashion.6.3 Therefore, the authors must be provided with a template: a mould for their article.
The development of such templates is closely linked to the editorial policy and Instructions to authors of a particular type of publication. Given the necessity that storage of modular articles in a database must be a simple and automated process, the templates must, in their turn, be standardised by being compliant with the international standard for the definition of device-independent, system-independent methods of representing texts in electronic form: the Standard Generalized Markup Language (SGML) [ISO, 1986].
Starting from the modular model, creating a Document Type Definition (DTD) for modular articles is straightforward. The DTD defines the structure of this type of document and the tags that can be used to encode the structure of actual modular articles according to the SGML rules.6.4 A style sheet then determines how the tagged article is presented on screen or on paper.
The authoring tools must include the following templates:
The basic problem-solution pattern of scientific articles can be laid out in a map that provides an overview of the components the author has to create. The author can use that general map as a starting point for the Map of contents of the article he is creating. For that purpose, he requires a `map-making kit' consisting of graphics software complemented with basic templates for the creation of a particular type of publication in a particular journal. The domain and genre specific templates must allow the author to customise his presentation within the limits established by the journal. The map-making kit must:
As we concluded in chapter 5, identifying and expressing the different relevant relations is a complicated task. However, that task can be alleviated by `link tools' for the generation, characterisation and presentation of the links.
The author must be able to refer to a specific part of any new or published module, not just to the module as a whole. In the current version of the Hypertext Mark-up Language, HTML 4.0 [Ragget et al., 1998], a hyperlink to a particular point in a node is possible, but not practical. The first drawback is that it requires an anchor at the appropriate location in the target, and that anchor can only be inserted there by the author of the cited article, not by the author of the citing article. The second drawback is that there is no indication where the relevant part stops (i.e. where the reader can stop reading according to the author of the citing article). These problems may be solved by the development of the Extensible Markup Language (XML). Draft specifications are available of an XML Linking Language (XLink) and an XML Pointer Language (XPointer) [Maler and DeRose, in progress]. Using these languages it is possible to specify a new link annotating an existing document. It is also possible to specify links to multiple destinations, which can be targeted at specific places inside a document or specific portions of a document, even when the author had not specified an anchor at that particular place.
The system must keep track of both ends of a link (the source and the target). The navigation menu shows not only the links leading from the module at hand to other modules, but also the links from other modules to the module at hand as a target. A link to the module at hand may be created after the publication of this module; therefore, the navigation menu and the map of contents should not be stored hardwired into the modules, but be generated on the spot when the module is consulted, based on the collection of characterised links leading to and from the module.6.5
For the reader, it is not only important to know that particular modules are connected by a link of a certain type, but also to know who created that link and within what context. In other words, in order to meet the authenticity and integrity requirements of a scientific article, the links must be as fully characterised as the modules and all other `published items'.
When a link is created by the original author at the same time as its source module, its bibliographic characteristics are implicitly determined by the bibliographic characterisation of the source module. This is the case for the links that we have created and discussed in this thesis, because we have concentrated on the creation of entire modular articles rather than on the addition of individual modules or links to published work. However, in a modular environment new links can be created by new authors between existing modules. These `added' links should not only be characterised by the relations they express, they should also be endowed with explicit bibliographic labels.