The interactive effects of a student's conceptual level and the structure of the teaching environment are examined. Concept level for the purposes of this study is identified as maturity in information processing and in interpersonal competence. Thirty-three preservice teachers were classified as being at a high, middle, or low conceptual level. Instruction techniques for these students were considered as "high structure" (criteria highly controlled by the instructor) and "low structure" (criteria minimally controlled by the instructor). Results indicate that low-concept-level learners benefit more from high-structure instructional environments than from low-structure environments, and, conversely, high-concept-level students profit most from low-structure environments and are less affected by the variation in structure. (JD)