PLATO (PROGRAMED LOGIC FOR AUTOMATIC TEACHING OPERATION) IS A DEVICE FOR TEACHING A NUMBER OF STUDENTS INDIVIDUALLY BY MEANS OF A SINGLE, CENTRAL PURPOSE, DIGITAL COMPUTER. THE GENERAL ORGANIZATION OF EQUIPMENT CONSISTS OF A KEYSET FOR STUDENT RESPONSES, THE COMPUTER, STORAGE DEVICE (ELECTRIC BLACKBOARD), SLIDE SELECTOR (ELECTRICAL BOOK), AND TV DISPLAY. THE CENTRAL ELEMENT OF THE TEACHING MACHINE IS ILLIAC, A MEDIUM-SPEED, GENERAL PURPOSE, DIGITAL COMPUTER. THE STUDENT COMMUNICATES TO THE MACHINE BY MEANS OF A KEYSET WHICH ALLOWS HIM TO SUBMIT ANSWERS TO THE MACHINE'S QUESTIONS, AND CONTROLS THE MACHINE'S PRESENTATION OF MATERIALS. THE MACHINE COMMUNICATES TO THE STUDENT BY MEANS OF A CLOSED CIRCUIT TELEVISION IN TWO MODES--AN ELECTRONIC BOOK IN WHICH INSTRUCTIONAL MATERIAL IS ON A SET OF SLIDES, AND AN ELECTRONIC BLACKBOARD. THE LOGIC BY WHICH INSTRUCTION TAKES PLACE IS DETERMINED BY THE PROGRAMS WITHIN ILLIAC. THE CURRENT LOGIC REQUIRES THE STUDENT TO GO THROUGH A FIXED "MAIN" SEQUENCE OF SLIDES, ANSWERING CORRECTLY EACH QUESTION POSED IN THE COURSE OF THIS SEQUENCE. HE MAY AVAIL HIMSELF OF SUPPLEMENTARY MATERIALS IN QUESTIONS HE FINDS TROUBLESOME. IMPORTANT FEATURES ARE--EACH STUDENT MAY GO THROUGH THE MATERIAL IN A MANNER AND AT A SPEED OF HIS OWN CHOOSING, THE MACHINE ACCEPTS AND DISPLAYS CONSTRUCTED ANSWERS, AS WELL AS THE MORE RESTRICTIVE ANSWERS TO MULTIPLE CHOICE QUESTIONS, AND THE EQUIPMENT AND THE PROGRAMED LOGIC APPEAR TO BE SUFFICIENTLY VERSATILE SO THAT ONE CAN CHANGE FROM ONE SUBJECT TO ANOTHER BY SIMPLY REPLACING SLIDES. TEACHING STUDIES HAVE SHOWN THAT PLATO IS GENERALLY EFFECTIVE AS A TEACHING DEVICE.