The purpose of this study was to examine the relationship between science curricular treatment and achievement in middle school. A repeated-measures ANOVA applied to standardized test score data from students, n = 3,135, determined relative growth from 5th to 8th grade. Findings show achievement scores from schools offering a choice of advanced and regular science was slightly higher. Gender played no significant role. Race was a significant factor in all scenarios as was free/reduced lunch status. Results showed no significant relationship between the type of science class and the category assigned by standardized achievement scores, and that curricular differentiation may not be the most effective way to enhance science education. Grit may have more impact on achievement than curriculum treatments. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]