Repertory hypergrids for large-scale hypermedia linking

Abstract

Creation and maintenance of links in large hypermedia documents are difficult. Motivated by an application to a federal clinical practice guideline for cancer pain management, we have developed and evaluated a repertory grid-based linking scheme we call repertory hypergrids. Harnessing established knowledge acquisition techniques, the repertory hypergrid assigns each "knowledge chunk" a location in "context space". A chunk links to another chunk if they are both close in context space. We have developed a program to convert the hypergrid and associated knowledge chunks to HTML and have made the hypermedia clinical practice guideline available on the World Wide Web. To evaluate the scheme, we conducted two analyses. First, we conducted a protocol analysis using the paper-based guidelines. Six users of the guideline addressing typical cancer pain management tasks made 30 explicit links. The repertory hypergrid using a neighborhood size of 16 captures of 24 of these links. With optimization, the repertory hypergrid captures 27 of the links with a neighborhood size of 14. Second, 18 users addressed the same tasks, six using the paper-based guideline, six using the hypermedia document with repertory hypergrid-created links ("TALARIA"), and six using the hypermedia document with randomly selected links ("Random TALARIA"). TALARIA users found the required information significantly more quickly than either the users of the paper-based guideline or of Random TALARIA, with no loss in accuracy.