THE OVER-ALL OBJECTIVE OF THIS STUDY WAS TO PROVIDE SPECIFIC INFORMATION CONCERNING THE EFFECTIVENESS OF COMPUTER-BASED INSTRUCTION IN TEACHING THE USE OF THE LIBRARY. THE SIXTY-SIX STUDENTS WHO PARTICIPATED IN THIS THREE SEMESTER EXPERIMENT WERE UNDERGRADUATES ENROLLED IN LIBRARY SCIENCE 195, A COURSE OFFERED FOR CREDIT BY THE UNIVERSITY OF ILLINOIS GRADUATE SCHOOL OF LIBRARY SCIENCE. THE EXPERIMENTAL GROUP RECEIVED THEIR INSTRUCTION BY THE LECTURE METHOD. THE AUTHOR WROTE A 923-FRAME PROGRAM, EXCLUDING THE "HELP" SEQUENCES FOR THE PLATO TEACHING SYSTEM. THE FOLLOWING ARE SOME OF THE CONCLUSIONS DRAWN FROM THIS STUDY-- 1. STUDENTS UNDER BOTH TREATMENTS MADE SIGNIFICANT GAINS IN THEIR KNOWLEDGE OF LIBRARY USE, 2. THE EXPERIMENTAL AND CONTROL GROUPS DID NOT DIFFER SIGNIFICANTLY IN THE AMOUNT OF KNOWLEDGE GAINED AS A RESULT OF THEIR RESPECTIVE TREATMENTS, 3. IT WAS SEEN THAT IN CLASS THE EXPERIMENTAL GROUP COVERED THE SAME AMOUNT OF MATERIAL IN LESS TIME THAN THE CONTROL GROUPS, 4. MUCH MORE TIME WAS REQUIRED FOR THE INITIAL PREPARATION OF PLATO LESSONS THAN CONVENTIONAL LECTURES, 5. SUBSEQUENT PREPARATIONS FOR PLATO LESSONS REQUIRED MUCH LESS TIME THAN SUBSEQUENT CONVENTIONAL LECTURE PREPARATIONS, 6. PLATO INSTRUCTION REQUIRED LESS TEACHING ASSISTANCE THAN CONVENTIONAL LECTURES, 7. INSTRUCTOR'S TIME DURING ADMINISTRATION OF LECTURES FAR EXCEEDED THE AMOUNT NEEDED FOR THE ADMINISTRATION OF THE PLATO METHOD. (AUTHORS)