A study of ways in which users conduct subject searches with an online public access catalog (OPAC) was performed at the College Park Campus of the University of Maryland. Both process (search patterns) and product (search results) variables were examined with respect to individual characteristics of 39 volunteers, many of whom were master's level (64%) library science (62%) students. The OPAC used is menu-driven, and provides access through author, title, combined author/title, subject (LC subject headings), keyword, and number; boolean searching was not fully implemented at the time of the study. Each subject was asked to complete two search tasks, one straightforward and easy to complete, and the other open-ended and more difficult. They were then asked to list the call numbers of relevant items and to fill out a questionnaire designed to ascertain user satisfaction and demographic information. Results were considered for three criterion measures: user satisfaction, number of hits, and relevancy score. It was found that (1) the subjects used the OPAC with relative ease and the degree of success and satisfaction obtained was relatively high; (2) most subjects preferred subject heading to keyword searching, and (3) there was no evidence of strong relationships between search type or search results and individual characteristics. (BBM)