2/203.3.10 Problems with First-Generation WWW Servers
As mentioned in the last section, there are some important features, needed for online education which are not yet implemented in the first generation WWW solution. Let us discuss some of them:
- User and group management: When a first-generation WWW server is used, everybody can access every page. When you want to charge people for an online course, you do not want the course material available for everybody, but just for students who paid for the course. Besides, the more people who use a server the slower everything gets. When you want to log student behavior, or provide private group discussions, there is definitely the need for user authentication. In addition to single user rights, group access rights are also important. When you deal with groups of users like students of a certain class, they provide an easy means for access control.
- Structured Documents: In the last section I mentioned that even if the course material is presented as hypertext, a hierarchical structure of the material is still very important. First generation WWW servers do not provide a proper means for structuring documents. Only through intelligent linking can a hyperdocument have a hierarchical structure. Then, of course, it is very hard to insert new documents and ensure consistency.
- Better navigation tools: To avoid the syndrome known as ``lost in hyperspace'', special navigation maps, showing the user where the current document is located in the database, are needed. Besides, documents which have already been read by the user should be marked as such, and this information should not be stored on the client side, but rather on the server to enable users to use different clients without losing the information.
- Link Management: On WWW servers, hyperlinks are embedded in HTML documents. They are static and always visible. If you stored links in a separate database, you would be able to attach user rights to them. E.g., a teacher could see more links in a document than a student. Students could even add personal links, which are just visible to them, even though they are in the official course material. Furthermore, to make the students read the course material in the right order, you could insert the documents one by one, but you do not want links from the previously inserted documents, which lead to new document, to be visible before you have inserted the new documents. Using bidirectional links, which check the existence of their destination anchor, would make this possible without any maintenance work.
- Multiple versions of documents: If you want to present the lecture material to your students during a synchronous lecture, either in a classroom with a video projector or over the Internet, the use of the prepared course WWW pages will cause an information overload on the screen. What would be preferred, is a ``light'' version of a document which looks like an overhead slide.
- Audio and video conferencing: For synchronous communication, text-based technologies are not always the optimal means. Audio and video conferencing tools should be embedded into WWW documents to enable online lectures, and to allow better collaboration among participants of online courses.
Some of these features have already been implemented in earlier hypertext systems, like Brown University's Intermedia3.2.5, but, unfortunately, these systems no longer exist. Probably, the simplicity of the World Wide WWW was the reason for its fast growth. One system that has survived is Hyperwave, a so called second-generation hypermedia system, which has been developed at Graz University of Technology under the name Hyper-G since 1989. The developers of Hyperwave implemented many of the features lacking from the WWW. It will be discussed in detail in the next section, and is essential for the teleteaching project discussed in the last chapter of my thesis.
Another way of adding more facilities to the WWW is the idea of producing HTML pages on-the-fly, using the content of a sophisticated database. CGI scripts can be used as an interface between the WWW server and the database. Then, of course, link management has to be implemented with CGI scripts because it is not part of existing database systems.
In conclusion, we can say that the World Wide WWW could play a major role in education. Hopefully, not only in distance education where the traditional ``sending paper by postal mail'' is out of date, but also in addition to the traditional classroom as a 24 hour communication and collaboration tool.