The purpose of the National Association of Secondary School Principals (NASSP) Learning Style Profile is to provide educators with a well-validated and easy-to-use instrument for diagnosing the cognitive styles, perceptual response tendencies, and study/instructional preferences of middle level and senior high school students. The Learning Style Profile offers school practitioners a way to personalize the instructional process, to identify the dominant stylistic characteristics of students, and to plan instruction accordingly. The articles in this monograph offer a short course in the development, theoretical base, and utilization of the NASSP Learning Style Profile. The conceptual and practical issues of the Learning Style Profile are also explored. Chapters include: (1)"Development of the NASSP Learning Style Profile" (James W. Keefe); (2) "The NASSP Learning Style Profile and Cognitive Processing" (Charles A. Letteri); (3) "Using the NASSP Learning Profile" (Barbara Ferrell); and (4) "A Learning Style Approach to Effective Instruction" (John M. Jenkins). (JD)