OPACS - A RESEARCH REVIEW

A large number of studies have investigated the Online Public Access C atalog (OPAC). This article identifies and analyzes studies that have been published since 1990, excluding comparative OPAC reviews, system descriptions and opinion pieces. it discusses the problems facing rese archers as a result of the many variables at play in OPAC research-use rs, library settings, search strategies, and systems-as well as the di fficulty in defining the crucial concept of ''relevance.'' Data collec tion methodologies are examined: experiment, interviews and questionna ires, observation, think aloud, and transaction logs. Research results are considered in terms of known-item searches and subject searches. Research recommendations are grouped under three headings: bibliograph ic record enhancement, search capabilities, and interface design.