Although research on teacher planning is in its infancy, Jackson (1965) reveals various teaching and planning processes have been studied and a distinction made between preactive and,interactive teaching. During preactive teaching, or periods of time when teachers do not interact with students, teachers have the most time to reflect on the total instructional process. Doyle (1979) maintains that all planning is affected by what teachers know about classrooms, an idea consistent with one of Colbert's (1979) teacher function categories: diagnostician. Assuming, as did Zahorik (1970), that general and haphazard planning leads to wasteful and unproductive plans and that preservice teachers' classroom knowledge is more limited than experienced teachers, we designed a study to examine the type of information preservice teachers consider when reflecting on the teaching process. Current research findings regarding teachers' planning influenced our choice of pupil characteristics, teaching activities, and evaluation criteria as areas of inquiry. Choices also were predicated on our recognition of teacher education programs' focus on all three areas with possible differences of emphasis on each for elementary and secondary preservice teachers. Therefore, we formulated two questions: 1. What pupil characteristics, teaching activites, and evaluation criteria do elementary and secondary preservice teachers consider and/or use? 2. Are there any pre/post associations in the type of information considered by elementary and secondary preservice teachers? Despite the paucity of research in this area, Zahorik (1975) and Yinger (1978) found that activities, subsuming content and materials as elements that help define the activities, were the most frequent planning concern of teachers. In contrast, Morine (1978) found that teachers paid little attention to pupil backgrounds, while Yinger (1978), on the other hand, found that attention was given to pupil characteristics during the planning process, but was not referred to in the plans themselves. Finally, both Yinger and Morine found that evaluation procedures were almost totally neglected by teachers during planning.