EN
The paper includes the description and analysis of the results of empirical studies aimed at the comparison of various academic library OPACs configurations as features supporting opportunistic acquisition of information about scholarly literature. The studies in question consisted of experiments with the use of 22 different search statements followed by the analysis of results not requested but retrieved and displayed by the system alongside the retrieval of other resources. The experiments were conducted on 33 Polish library OPACs operated with 8 various computer systems in a three-month period (May-July 2007). The studies proved the interdependence of OPAC solutions, search statements and opportunities to retrieve publications which cannot satisfy users' core information needs but may answer or induce other information needs of those persons.