To test the effect of library instruction on learning basic knowledge and skills in using reference tools, 33 Ball State University students received such instruction in a course on information resources in libraries. In control groups from basic literature courses, 39 students received course-related library instruction and 81 students received no instruction in library use. Students were pre-tested and post-tested using the Feagley Test, and responded to questionnaires for demographic information, previous library instruction, library use, and attitudes. Statistical analyses of mean test scores confirmed the hypothesis that students who have taken a course in library instruction will learn to use library reference tools more effectively than those who have not. Descriptive data revealed that previous library use and work experience had more effect on library ability than class level, subject majors or previous library instruction. The study concluded that students will benefit to a significant degree from taking a formal library instruction course. Further systematic and scientific research was suggested in library instruction evaluation, and in the development of a standardized library skills test. Bibliography and questionnaire are appended. (KP)