The impact of an introductory library skills course is evaluated through the use of a difference of means test, the t-test for significance. The purpose of the course is to provide a basic introduction to the efficient and effective use of academic libraries and their resources. Each of 55 undergraduates was pretested to determine his/her entry level of expertise. The test and the course covered eight competency areas: terminology, card catalog, subject heading, heading arrangement, reference materials, biographical information, choice of index, and periodical indexes. At the conclusion of the semester, students completing the course were retested using the identical test supplemented by an attitudinal test for feedback. The paper closes with a brief discussion of suggested improvements for both the course and the evaluation tool. (Author/RAA)