Disorientation in hypertext: the effects of three text structures on navigation performance.

A study is described which examines the effects of two hypertext topologies (hierarchy and non-linear) on navigation performance compared to a linear version of the same document. Subjects used the document to answer 10 questions. After a distraction period, subjects returned to the document to locate five specified nodes. Speed and accuracy measures were taken, and the subjects' own evaluation of their performance was assessed using a questionnaire. The results showed that subjects performed better with the linear text than with the non-linear text, while performance on the hierarchical document fell between these two extremes. Analysis of the questionnaire data confirmed these differences. The results are discussed in terms of their implications for computer-assisted learning systems.