The purpose of this study was to compare the effects of various teaching practices and classroom organizational patterns upon achievement and understanding of science of students studying materials of the Nebraska Physical Science Project (NPSP), an integrated chemistry-physics course, and to investigate these practices and patterns and the role perceptions of their teachers. The study sample consisted of 198 students and their 12 teachers. Students were given a battery of tests to ascertain aptitudes, teacher directiveness, and classroom organizational characteristics. The results of these tests and questionnaires were compiled and analyzed using the t-test and analysis of variance. Classes were grouped into lecture-demonstration or performance-sequenced categories for the purpose of comparing student achievement. Classes were regrouped into directive or non-directive categories to make comparisons of student achievement and to gain understanding of teacher role perception. Statistical analyses indicated no significant difference in achievement between groups. Recommendations based on this study included encouragement for NPSP teachers to feel free to use a variety of teaching styles and classroom strategies. (Author/CP)