Empirical Evaluation of Adaptive Annotation in Hypermedia.

Empirical evaluations of learning with hypertext have shown contradictory results. Adaptive hypertext was introduced to solve some problems when learning with hypertext. This paper reports on two empirical studies comparing different forms of adaptive hypertext. In the first experiment, four treatments were realized by a combination of adaptive annotation and incremental linking of hypertext. Results showed significant improvements in knowledge tests for subjects learning with adaptive annotation and incremental learning. In the second study, different forms of adaptive annotation were integrated in the World Wide Web-based learning environment AST (Adaptive Statistics Tutor). Results showed a significant interaction between previous knowledge of students and the adaptive annotation of the learning materials. Students who performed well in an introductory knowledge test seemed to work more intensively and successfully with a more supportive form of adaptive annotation, while students with less previous knowledge seemed to need more guidance and profit from a more restrictive form of adaptation. Three tables present data, and five figures illustrate the main pages of hypertext in the four experimental treatments and the interaction between the results of a preliminary knowledge test and the adaptive treatment. (Author/DLS)