To evaluate a method of content analysis, and as a step toward the specification of a conceptual domain for primary level science, extant instructional programs were analyzed. This paper reports an analysis of the introductory unit and three biological science units of the Science Curriculum Improvement Study (SCIS). The background of the program and the procedures for the analysis are described. The conceptual content is summarized. Problems encountered in the analysis and their implications for subsequent analyses are discussed. (Author/EB)