Accepting the idea that "professional activity in teaching is related to the closeness with which teaching decisions approach the individual learning needs of pupils" would necessitate several changes in the traditional approach to teacher preparation. First, courses would focus on the diagnostic decision-making aspect of teacher behavior. Second, the interactive aspect of teaching would be examined, and students would be exposed to various dimensions of classroom interaction and their relationship to diagnostic behavior. Third, instruction in large teaching systems (like the phonics approach in reading) would be broken down into component elements in order to prepare the teacher to fit instruction to a particular group of individual learners. At least four types or levels of laboratory experiences, or combinations of them, would be needed to implement such a revised teacher education program, including a training experience to aid students in identifying and gaining proficiency in using basic tools necessary for teaching, an experience focusing upon the diagnosis and analysis of teaching situations, an experience requiring requiring students to implement diagnoses in teaching situations with some control over variables, and an experience similar to student teaching or internship but directly focusing on the basic concept of professional behavior. (SG)