A model of the educational process and a derived procedure series for implementing an individualized instruction system are presented. The application of computer technology to individualized instruction requires an operational definition of the educational process in terms of school practices. A process model involving three major sets of variables, educational goals, individual capabilities and instructional means, with means a function of goals and capabilities, is outlined. Following upon this conceptual model, an instructional model and the functional basis of an individually prescribed instruction (IPI) system are developed as a sequence of operations. As instruction proceeds, performance is monitored and assessed, and necessary adaptations occur at subgoal decision points. The system is also evolutionary; it is able to compare interim student behavior and final outcomes with predictions of original operational functions and provide the basis for modification when appropriate. Experience obtained in introducing computer assistance into a currently operational IPI system is described at length, and system research abilities, including a cumulative data bank for basic learning and measurement studies, are discussed. (SS)