This paper approaches the task of defining basic teaching skills by identifying essential preactive skills. Piaget's model of cognitive development was used to determine the general goal of teacher training in preactive skills, to identify the three basic kinds of preactive skills necessary for teachers to learn, and to suggest the kinds of instructional processes to achieve the goal of changing the cognitive functioning of teachers so that they begin to move from the concrete operational level of development toward the formal operational level in their preactive teaching behavior. The three basic kinds of preactive skills identified were generating alternatives, selecting among alternatives, and altering existing circumstances. Specific behavioral objectives subsumed to each of these skills are presented. The instructional processes suggested to achieve these goals capitalize on the developmental processes of socialization and equilibration. The types of training materials to be developed to implement these processes provide background information on new instructional alternatives, simulated data on the given affecting instructional decision making, and peer interaction regarding contradictory instructional decisions. (PD)