Diagnostic instruments of the Individually Prescribed Instruction (IPI) Program measure pupil achievement in the IPI learning continuum. The IPI system employs the instructional unit to define progress in mathematics, reading and science. At the start of a school year, placement tests are administered to start the pupil in appropriate learning exercises. Unit pretests provide mastery criteria for objectives within a unit of work and help the teacher know what lesson material to prescribe for the pupil. Posttests measure the pupil's mastery of unit concepts after he has completed his assigned tasks. For each instructional unit, there is one pre- and one posttest. Curriculum embedded tests (CET) indicate when a pupil has learned a particular skill within a unit of work. The teacher plans the pupil's learning sequence and monitors his progress with the aid of these four kinds of tests. Examples of the tests and models for their use are included. (TI)