In reviewing Herbert J. Klausmeier's academic career, this paper discusses four major areas of his contributions: (1) cognitive learning and development (CLD); (2) individual differences and related educational provisions; (3) educational research as a field of scientific inquiry; and (4) teacher education. CLD, Klausmeier' major contribution, was centered around teaching and learning of concepts. A significant portion of research supporting his theory was conducted in schools and classrooms. Individual differences and related educational provisions concentrated on individual learners' differences and their learning and development. Important attributes of what Klausmeier called the "improvement-oriented" research method are: (1) a problem experienced by practitioners initiates the process; (2) research is planned to solve the problem; (3) research is planned using available knowledge; (4) solutions are tested for effectiveness; (5) practitioners develop skills for conducting research; (6) knowledge about the enterprise is generated; and (7) results are tested for generalizability. In the area of teacher education, Klausmeier recognized the need to prepare teachers to implement programs effectively and to know and apply principles derived from educational psychology. (JAZ)