Educational Research Institute of America (ERIA) conducted a one-semester pretest-posttest study of Science Dimensions to understand the effectiveness of the program in supporting students’ knowledge and understanding of the unit’s objectives. Participants included 14 teachers and 420 Grade 5 students from seven different schools across five states. Assessments were developed to assess students’ knowledge and understanding of the unit. Results indicated that student achievement growth from pretest to posttest increased statistically significantly. Similarly, student achievement growth for both the high- and low-pretest students increased statistically significantly.