This paper is concerned with the clarification and resolution of two basic defects of curricular and instructional research: vagueness as to what is being undertaken, and inattention to the logical aspects of evaluation. It introduces the concepts of curricular claim and instructional claim, clarifies the function and import of curricular claims, and sets forth the principles of curricular claim validation. The implications of these concepts and principles for both curricular and instructional research and educational program construction and evaluation are examined. (Authors/DDO)