INTERACTION IN INFORMATION-RETRIEVAL - SELECTION AND EFFECTIVENESS OFSEARCH TERMS

We investigated the sources and effectiveness of search terms used dur ing mediated on-line searching under real-life (as opposed to laborato ry) circumstances. A stratified model of information retrieval (IR) in teraction served as a framework for the analysis. For the analysis, we used the on-line transaction logs, videotapes, and transcribed dialog ue of the presearch and on-line interaction between 40 users and 4 pro fessional intermediaries. Each user provided one question and interact ed with one of the four intermediaries. Searching was done using DIALO G. Five sources of search terms were identified: (1) the users' writte n question statements, (2) terms derived from users' domain knowledge during the interaction, (3) terms extracted from retrieved items as re levance feedback, (4) database thesaurus, and (5) terms derived by int ermediaries during the interaction. Distribution, retrieval effectiven ess, transition sequences, and correlation of search terms from differ ent sources were investigated. Search terms from users' written questi on statements and term relevance feedback were the most productive sou rces of terms contributing to the retrieval of items judged relevant b y users. Implications of the findings are discussed.