Visualisation of semantic relations between nodes in hypertext-based learning systems

Abstract

The research described in this thesis is concerned with the design of hypertext-based learning systems. More specifically, it is concerned with investigating the effects of visualising semantic relations between nodes on learning in hypertext-based learning systems.One of the most commonly cited problems with hypertext is the distraction that stems from the high level of learner control in hypertext systems. This might partly be responsible for the fact that there are few evaluations of hypertext in education which have shown the strength of hypertext over other media in terms of learning outcomes. In order to ease the problem of distraction so as to improve the application of hypertext in education, an approach employing visible link-types is proposed. It is hypothesised that labelling links explicitly with semantic relations between nodes can lower the learner's cognitive overheads in making navigational decisions so as to improve learning. It is also hypothesised that this kind of labelling can make the conceptual model of the knowledge domain intuitively clearer to the learner and thus facilitate learning.A set of three empirical studies has been conducted to evaluate the effectiveness of the proposed approach in different situations, using different methodologies. The results found from these studies demonstrate that visualisation of semantic relations between nodes has potential for improving the use of hypertext for learning