The development of a single value revision indicator which would utilize learner performance data obtained from a pretest-posttest design to rank a set of instructional modules as to their relative need for revision is discussed. A set of procedures was developed in connection with the implementation of the Production, Implementation, Evaluation, and Revision of Instruction Modules (PIERIM) Model for design of instruction. A comparison of the similarities and differences between using the module in a conventional classroom environment and using it in a self-instruction environment are presented as a frame of reference for the analysis and interpretation of the learner performance data reported in Tables 1 and 2. The correlation coefficient (r =.83) indicated substantial agreement between the rankings of the instructional modules using the revision indicators derived from the learner performance data for Group I and Group II. This methodology appears to be one method for the better utilization of data derived from learner performance during the formative evaluation of instructional materials. (CK)