A Feedback Mechanism for Query

The Two-Level Hypermedia Paradigm sees an Information Retrieval System as consisting of a document network (the Hyperbase) and a descriptor (term) network (the Hyperindex). Query by Navigation is a process whereby the searcher gives a description of the Information Need by travelling through the descriptor network. This paper presents a formalism for expressing the eeects of traversing the Hyper-index on the elements of the Hyperindex. This formalism makes use of probabilities for modelling the searcher's behavious. The events which can occur during the search process are discussed and modelled. Some important properties, which are reasonable to demand of a retrieval system, can be proven to be valid if this formalism is adopted. A mechanism for assigning a measure of relevance to documents is presented. This uses the formalism mentioned above. An example will show the eeectiveness of The aspect of relevance feedback and its role in Query by Navigation is introduced by examining the diierent level on which the searcher can ooer information for weeding out unwanted sections of the search space. In order to illustrate the workings of Query by Navigation a small example is included .