The instructional model (IM) that is the basis of this evaluation resulted from the merger of two major Learning Research and Development Center (LRDC) projects--the Primary Education Project (PEP) and the Individually Prescribed Instruction (IPI) project. This paper examines the Center's publications relative to the problem of evaluation of such an IM and suggests new directions for summative evaluation. It emphasizes the importance of organizing ideas (educational theories) in evaluative research. Seven requirements of a theory of educational criteria are examined and a model is developed for combining information on student entering behaviors, educational treatment, and resulting student achievement. A list of 32 recommendations summarizes the goals for the future refinement of the IM. (JY)