Daniel M Germán

Towards a unified catalog of hypermedia design patterns

There has been a recent increase in the number of published design patterns for hypermedia. Some of these patterns have been evolving, while others have remained untouched. This paper attempts to list all the patterns currently known, tracing the different publications in which they have appeared. The patterns are scrutinized and refined: some patterns are unified into one; some are deemed special cases of other patterns; some patterns are renamed. At the same time, we propose to rewrite the patterns in a vocabulary that is uniform, and to use similar pattern templates. We then discuss the creation of a design patterns system, which organizes the patterns and assists the designer in the process of recognizing the problems and their potential solutions. Finally we propose a subset of the patterns which should conform a catalog of basic patterns; this catalog will attempt to address the most common problems found during the design of hypermedia applications.

Formalizing the Specification of Web Applications

As the size of Web applications grows, it becomes clear that we need better tools to deal with their growing complexity. The current trend has been to assist the developer during the implementation stage, with little or no emphasis in the design process. Formal specification languages allow the unambiguous description of the properties of a system without restricting its implementation. Formal languages can be used to verify properties about the design. We present in this paper Flash, a formal specification language for hypertext design. Based in set theory. Flash is a formal system that attempts to separate the different tasks faced during the design process. A Flash specification first formalizes the content of the application and its relationships. Then it collates that content into navigational composites. Finally, it specifies how those composites can be navigated. Each stage is clearly specified with precise, unambiguous syntax and semantics. Furthermore, Flash verifies properties such as completeness and type consistency of the specification.

Dynamic views of SGML tagged documents

Product information is more frequently being delivered as hypertext webs or documents because of the availability of the World-Wide Web and the associated communications infrastructure. However, this type of document with its large number of files and hyperlinks can become very complex and present significant usability problems for the creator, maintainer and user. Because of this complexity it becomes extremely difficult to implement and maintain dynamic views of a document, a supposed advantage of a hyperlinked structure. In this paper we analyze some of the causes for these usability issues, and then describe some approaches that are being used to make significant improvements to this situation.

Experiments with the Z interchange format and SGML

Standards, if widely accepted, encourage the development of tools and techniques to process objects conforming to that standard. This paper describes a number of experiments using available tools to process text containing Z specifications adhering to the existing Z Interchange Format. The experiments resulted in tools that could be used in specific programming environments where Z was used to describe software systems.

Dynamic Documents Over the Web

In general, software engineering practice includes document production as one of the activities that software developers need to perform during the software development process. According to Pressman (1992), most software development organizations spend a substantial amount of time developing documents, and in many cases the documentation process itself is quite inefficient. Pressman also mentions that it is not unusual for a typical software engineering organization to spend as much as 20 or 30 percent of all its software development effort on producing documentation. Thus, automated support for document presentation and production provides an opportunity for the developers to save time and effort and, consequently, to improve productivity.