Hypermedia and cognition

To discuss the relationship between cognition and hypermedia, it is necessary to distinguish between two kinds of applications: "One encourages those who wish to wander through large clouds of information, gathering knowledge along the way. The other is more directly tied to specific problem-solving, and is quite structured and perhaps even constrained" 20, p. 119. Applications of the first type appear as browsable databases-or hyperbases-that can be freely explored by a reader. In contrast, applications of the second type take the shape of electronic documents-or hyperdocuments-that intentionally guide readers through an information space, controlling their exploration along the lines of a predefined structure. Each type has its particular advantages and encourages different reading strategies. While the first one is better suited to support unconstrained search and information retrieval, the second one is more adequate for tasks requiring deep understanding and learning. As Hammond points out, it "may be fun and perhaps instructive, to open every door and peer inside, but there are many situations where learning is most effective when the freedom of the learner is restricted to a relevant and helpful subset of activities."