Some useful metrics on evaluating educational hypermedia designs

This paper reports our work in developing four new metrics to guide the development of CAL packages and to measure the the educational suitability of a given package. Our first metric, the multi-level compactness, is a summary index of the compactness at different hierarchies. The metric measures if teaching units are organized hierarchically while maintaining the local compactness within each teaching unit. The second metric, heterogenity, is then developed to measure how different types of documents are clustered together in a CAL package. However, this metric does not reflect how the structure of the different documents. This is remedied by the third metric, the guidance. It represents how the exercises/test documents are placed in the traversal paths of the content and reference documents. The first three metrics are focused on the structure of the education materials. The forth metric, crossing, is proposed to measure the help level amongst the materials. In order to verify the correctness of the first three metrics, a Java program has been developed. It provides an interface to calculate the values of the metrics for a given hyperlink of a WWW CAL package.