The concept of hypertext is generally credited to Vannevar Bush and his Memex proposal [Bush1945] but it has taken almost fifty years for the technology to become powerful enough to fully realize his ideas. In the meantime, there has been much discussion (and criticism) of traditional methods of education along with the characterization of alternate methods. The hypertext authoring project supports two such modes of education: collaborative and constructionist learning.
The collaborative approach, defined simply as learning through participation in a group, is not unique to the use of Mosaic (in fact, the Cognitive Architectures course previously included group discussions) but the project did increase interaction and a sense of cohesiveness among group members. The nature of the project required all group members to keep up with work in the classroom and outside readings in order that the document could be continually built. Thus, while it was important that individuals kept up with work in the course, the groups reinforced the material as well.
Most of the groups met outside class on a weekly basis. At these meetings the students did not necessarily work on the document together but decided on the features and ideas for new portions of the document and reviewed work that had been done in the previous week. Thus, their critical skills were being refined as each group worked to have a comprehensive and well-organized presentation.
Many students dislike group work because inevitably one or a couple of the students undertake the majority of the work. One of the advantages of this project was that tasks could be broken into manageable and measurable pieces (corresponding to the writing of some particular portion of the document) and each group member could instantly check on the progress of colleagues by simply browsing the Mosaic document. The students reported that their documents were indeed group efforts, based largely on their ability to balance the workload between group members at different points in the semester.
The constructionist approach to education can be summarized by this brief passage from Henry David Thoreau's Walden:
Which would have advanced the most at the end of a month,- the boy who had made his own jackknife from the ore which he had dug and smelted, reading as much as would be necessary for this,- or the boy who had attended the lectures on metallurgy at the Institute in the meanwhile, and had received a Roger's penknife from his father? Which would be the most likely to cut his finger? [Thoreau1989]A more rigorous definition of the constructionist philosophy may be found in [Harel1990] and a discussion of its relation to hypertext in [McKnight et al.1993].
The cognitive architectures project supported the constructionist paradigm in two important ways. First, because of the relative simplicity of learning HTML, students did not have to invest a tremendous part of their effort in the class to learning the markup language. Rather, their time could be spent on the document itself, taking advantage of their own interests and expertise and the power of HTML to give the group documents an individual (and creative) touch. For example, ``surfers'' found links to documents at servers across the country to supplement their descriptions of particular architectures. Programming-oriented students built tools for building and using their document such as a text-based keyword searcher. Students especially interested in a particular architecture could do further reading, elaborating the document with findings not presented in class and a more first-hand evaluation of the architecture. Thus, the nature of the project supported a degree of creativity and expression not normally available to someone simply writing a term paper for a technical class.
However, the second and more important advantage of using the hypertext approach, which is also in accord with the constructionist philosophy, is that the hypertext documents encouraged a non-linear analysis of architectures. Relationships between the components of an architecture, the design decisions that resulted in those components, and the resulting behavior of the cognitive architecture system often proved to be a densely interconnected series of trade-offs and compromises, each affecting the other. The ability to use hypertext in these documents not only facilitated the presentation of these complex relationships but student understanding as well. By the end of the term, the students were not only able to identify the features of the architecture (a low or first-level analysis) but also were asking insightful questions about these relationships, based almost directly on what they had learned in designing and writing their documents. Thus, the ability to organize the information in a non-linear way facilitated the students' understanding of the information, building a framework for deliberate analysis of any cognitive architecture.
Before examining the approaches taken by the individual groups, two reservations about the use of hypertext for this type of project should be mentioned. First is the problem of evaluation. A typical term paper may be about twenty pages; many of the individual architectures contained almost that much text. In addition to the size of the resulting documents, examining all the links in a hypertext document is difficult. Finally, the creative component is also difficult to evaluate. How does one measure a more extensive but straightforward analysis to a superficial one that included additional features? These observations suggest that making a fair and complete judgement of student work is more difficult with hypertext than when grading papers.
The second drawback of this particular hypertext authoring project was that the amount of information that had to be included in each document necessitated group work and a wide but shallow analysis. Certainly individual work and deep analysis are possible using hypertext but, for this class, an individual term paper was required of each student, requiring a more penetrating analysis of a few individual architectures. Thus, by combining the hypertext project with a more traditional assignment, both a breadth and depth of understanding was assured for each student.