Protocol materials are defined as records of human behavior in either (1) unaffected or (2) selected or simulated situations. In the first definition, instruction is centered on the results of an analysis of the situation. In the second, theoretical elements provide the basis for selecting or simulating the situation. In either case, the protocol material is the major source of information for thought. The use of protocol materials is based on at least five assumptions centered around the skills which protocol materials are designed to produce in teachers. These skills are observation, diagnosis, analysis, interpretation, and theory construction. Assumption 1 is that when decisions are based on these skills teaching will be more effective. Assumption 2 is that if decisions are not based on these skills, teaching will be less effective. Assumption 3 is that hierarchical sequences of these skills can be developed and presented during instruction which will cause the learner to move from knowledge to theory-based application. Assumption 4 is that protocol materials will give the teacher a better understanding of theory. Assumption 5 is that teaching is an activity which can be subjected to careful analysis. (For each of these assumptions, one or two tasks essential to testing are mentioned.) (MK)