This study was designed to determine if students taking junior high school science would receive greater understanding and retention of science principles and procedures from the Earth Science Curriculum Project (ESCP) than would students taught grneral science via the lecture-demonstration method. No attempt was made to group the students (28 in all) by IQ. At the end of the fourth six-week period, both groups were given the Test on Understanding Science Form W. Teachers used in the ESCP sample had received training for the use of this curriculum. All teachers were certified to teach science at the junior high school level. A two way analysis of variance method was used to analyze the data. Each of the three parts of the TOUS was analyzed separately as well as the total test scores. In Area II and III of the TOUS and in the total test scores, there were significant differences at the .05 level in favor of the ESCP group. Analysis of test scores of lowest academic level students from each group revealed the lack of significance in any single area or total test scores, indicating that, for these students, neither of these methods was superior to the other. (Author/EB)