Seventy tenth grade English students participated in a study comparing the effectiveness of two composition curricula for improving writing skills. The investigator-designed writing curriculum was based on R. M. Gagnes' hierarchy of intellectual skills (verbal chains, discriminations, concrete concepts, defined concepts, rules, and higher-order rules) and emphasized items of nonverbal communication. It was compared to a commercially published curriculum that used a literary model for developing written elaborating skills. The comparisons the study addressed included the differences in the written elaborating skills the students acquired and the interactions between sex and treatment and between school and treatment. The results indicated that the quantity of writing was not affected in either treatment, that females were more verbal than males, and that students significantly increased their elaborating skills in descriptive writing with the experimental writing curriculum. (AEA)