MOST OF THE ADVANTAGES GAINED FROM USE OF A COMPUTER ARISE FROM CHANGES IN THE BASIC DESIGN OF THE INSTRUCTIONAL SYSTEM, NOT FROM THE MACHINERY ITSELF. THE SYSTEMS APPROACH TO LEARNING, WHICH IS A CONCOMITANT OF COMPUTER ASSISTED INSTRUCTION, IS CHARACTERIZED BY BEHAVIORALLY DEFINED OBJECTIVES, DIAGNOSIS OF THE LEARNER'S STATUS BY MEANS OF PRETESTS, ACTIVE PARTICIPATION BY THE LEARNER, AND FEEDBACK TO THE LEARNER. A COMPUTER IN THE LEARNING SYSTEM HAS THREE BASIC FUNCTIONS--(1) A SIMULATION MEDIUM FOR STUDENT INSTRUCTION IN DECISION MAKING PROCESSES, (2) A MEDIATING AND CONTROLLING ELEMENT FOR SELF-INSTRUCTIONAL DEVICES OR TEACHING MACHINES, AND (3) AN INFORMATION BANK AIDING IN DIAGNOSIS OF STUDENT LEARNING PROBLEMS AND PRESCRIPTION OF APPROPRIATE TEACHING STRATEGIES. OTHER AREAS OF USE FOR COMPUTER BASED SYSTEMS ARE SCHEDULE MAKING, STUDENT DATA PROCESSING, DATA FILES, LEARNING CENTERS, MANAGEMENT DATA PROCESSING, RESEARCH, AND VOCATIONAL TRAINING. (WO)