Research on interactive thinking has revealed that teachers make interactive decisions in response to students' behavior and to the flow of the activities or routines they have established based on their planning. The purpose of this study was to describe the interactive information processing of preservice teachers, and to identify similarities and differences among the interactive thoughts and decisions of elementary and secondary preservice teachers. Twenty undergraduate student teachers participated in the study. During the final weeks of student teaching, the subjects were videotaped conducting lessons of their own design and then responded to stimulated recall interviews while watching the tapes. The results of the study indicated that each group reported more pupil-related decisions than any other type. However, there were differences in the patterns of emphasis in the types of interactive decisions of the participants. Elementary teachers placed a dominant emphasis on pupil-related decisions, while secondary teachers were more content-oriented. The findings from case studies provide a close look at the interactive thoughts and decisions of two exemplary student teachers. Charts illustrate patterns of interactive thinking, and appendices contain descriptions of the interview procedure and coding system used in the study. References are included. (JD)