Described are the procedures whereby data from teachers and children may be collected in classrooms. The techniques of interaction analysis (including matrix analysis) are applied to the collection and analysis of these data. The categories applied to the classroom behaviors of teachers and students have been developed specifically for the Science Curriculum Assessment System (SCAS). SCAS Classroom Interaction Categories place classroom behaviors into two major groups: teacher behaviors and student behaviors. Student behaviors are further categorized into: (1) those behaviors which are related to the lesson and (2) those behaviors which are not related to the lesson. Each of these two categories are further subdivided into ten specific student behavior categories. Teacher behaviors are divided into two major groups: (1) teacher interactions with less than seven children, and (2) teacher interaction with more than six children. These behaviors are each divided into ten categories. In using the SCAS particular emphasis has been placed on identifying changes in the child's perception of his environment, the child's classroom behavior, and the teacher's classroom behavior. This paper reports relationships among variables that have been investigated with 250 children and 27 teachers in Grades K-6. [Not available in hardcopy due to marginal legibility of original document.] (BR)