The purpose of the 1968-69 investigation was to determine the applicability of a curriculum evaluation model to investigate high school students' achievement in three physics courses (traditional physics, Physical Science Study Curriculum, and Harvard Project Physics). Three tests were used to measure student progress: The Dunning-Abeles Physics Achievement Test, Form E., the Wisconsin Inventory of Science Processes, and the Watson-Glaser Critical Thinking Appraisal, Form YM. The classroom verbal behavior of each class was recorded on audio tapes and quantified using Flanders' Verbal Interaction Analysis system. The results of the study indicate that the students exhibited greater change in physics content mastery than in understanding science processes or in critical thinking, although there was a significant increase in all three components. No specific curriculum was found to be more effective in enhancing student ability-growth in any of the three tested components (physics content, understanding science processes, and critical thinking). The total classroom verbal interaction patterns were found to differ among curricula and between high and low achieving classes, leading to the judgement that there is a relationship between classroom verbal behavior and a physics curriculum as well as a relationship between classroom verbal behavior and student achievement. The funds for this doctoral dissertation were provided by the U. S. Department of Health, Education, and Welfare. (Author/TS)