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Information retrieval (IR) is concerned with the representation, storage, and retrieval of documents or document surrogates. The output of an IR system in response to a user’s request consists of a set of references which are intended to provide the user with information relevant to his or her information needs as expressed by a query.1 Conventional information retrieval systems operate on large-scale computing systems in an environment where direct access to system facilities is generally limited to search intermediaries and to a few researchers who have been trained to use somewhat complex user—system interfaces. However, poor query formulations and inadequate user—system interaction may still occur even with skilled users. For example, Cleverdon1 has noted that “if two (trained) search intermediaries search the same question on the same database on the same host, only 40 percent of the output may be common to both searches.” Since skilled users often find it difficult to formulate effective search requests and to interact usefully with document retrieval systems, less competent users may be faced with insurmountable problems. This situation is especially critical at the present time; a large number of casual users will soon obtain access to very large information resources through the combination of powerful microcomputers and optical storage technology. |
