Purpose of this paper: A study examining search goal redefinition during users' interaction with information retrieval systems is reported. Methodology: The study utilised transaction logs from the OCLC FirstSearch service. Within each search session, logged queries were coded chronologically, according to their conceptual relationships, and indices of goal redefinition were constructed. Redefinition levels for different databases were compared, and certain features were isolated for examination as possible redefinition factors. Findings: The transaction log analysis showed that different databases induced goal redefinition to different extents and identified several factors which can contribute to goal redefinition, including the presence of abstracts and hyperlinking descriptors. On the other hand, no evidence was found to indicate that abstract length has much effect on redefinition, nor hit rate or retrievability of records. Research implications: The research needs to be followed up using other methodologies and other information retrieval systems. A range of other possible factors affecting goal redefinition should be investigated. Value: The paper shows that system feedback affects not only strategy, but also higher levels of information seeking behaviour interaction. This aspect of user-system interaction has rarely been researched. An index of goal redefinition and an interpretative form of transactional log analysis are put forward as means by which it may be investigated.