Individually Prescribed Instruction (IPI), an experimental instructional method for planning and conducting a program of studies tailored to the learning needs and characteristics of each student, has been in operation in suburban Pennsylvania's Oakleaf elementary school since 1964. Oakleaf's IPI program, which covers the subject areas of mathematics, reading, primary science, and spelling, requires no grades or basic textbooks. The program is based on specific behaviorally stated instructional objectives which are grouped into meaningful sequences representing different levels of progress. IPI allows the teacher to diagnose a child's relative progress on an individual basis and to prescribe appropriate instructional tasks which will enable the child to move on to the next curriculum level. Limited testing and the general evaluations of teachers and administrators working in IPI schools indicate a favorable improvement in student achievement. However, evidence on the effects of IPI is still fragmentary. Three to 5 years of perfecting IPI in demonstration projects similar to Oakleaf's, as well as a retraining program for administrators and teachers, will be required prior to extensive evaluative research. (JH)