Hypermedia and free text retrieval

Hypertext provides a method of accessing document bases in which the user is in control and simply browses through the document base to find interesting documents. However, when document bases become very large there can be a heavy overload involved in creating links between all possibly relevant documents. Free text retrieval (or relevance based retrieval) systems provide users the ability to search vast amounts of information with a free form textual query (e.g. an English sentence). As free text retrieval systems have to calculate a description (approximation to the meaning) for each document they cannot easily cope with non-textual documents. As a result of considering these two traditional methods of information retrieval a hybrid model has been developed and used in the prototype application described. This model allows users to start an information search by use of a free text query and then browse through the set of matched documents and follow any hypertext links to other documents. The main advantages to be gained by the hybrid model are improved access to very large document bases and improved access to non-textual documents