The findings of a study conducted to evaluate the effectiveness of a visual display illustrating use of the card catalog in a university library are presented. The evaluation focused on the major goal of the display, which was to provide new information to library users. A questionnaire designed to measure a respondent's knowledge of the various aspects of the card catalog presented on the 12 posters was distributed to library patrons and four classes in the sociology and psychology departments a week before the display, three weeks after its removal, and a year later. Findings indicate that 57 percent of the library users looked at the display, as did 30 percent of the class members, with all that looked having a higher percentage of wrong answers as well as a higher percentage of correct ones. The increase in user knowledge after reading the posters was negated by a corresponding increase in incorrect knowledge about the card catalog. Conclusions suggest emphasis on directional rather than instructional aids, with library instruction being viewed as the most effective way to impart information about library resources and their use. (MBR)