Public schools in the state of Texas are required by the Texas Education Agency to administer five state exams to high school students consisting of Algebra I, Biology, English I, English II, and U.S. History. These exams play a big role in school accountability and in high school graduation. For this reason, many schools develop intervention programs to increase student passing rates. This study focused on an intervention program known as Masters Camps that was created in an effort to increase STAAR biology scores. The problem was that the Masters Camps were never evaluated for their efficacy as an intervention to improve STAAR biology averages at an underperforming socio-economically disadvantaged high school in South Texas. The purpose of this quantitative comparative study was to evaluate the intervention by investigating if there were differences among students who participated in zero, one or two Masters Camps. Two conceptual frameworks guided this study. The outcome of learning was framed in the concept of functionalism. The construct of extracurricular activities framed the independent variable of the study which was the intervention of Masters Camps. All students who participated in one and two Masters Camps were counted. An average of these two groups was calculated and the same number of students was randomly selected from the control group so that all groups were roughly equivalent in number. One research question was investigated to determine differences in STAAR biology scores among students who participated in zero, one, or two master camps. A one-way ANCOVA statistical procedure was used to determine the effect of Masters Camps participation on STAAR biology scores. The results of the study which included 62 participants found that Masters Camps attendance had no statistically significant impact on student STAAR biology scores. The statistics indicated a small effect size with a partial [eta-squared] value of 0.006. Though students who attended two Masters Camps had higher average STAAR biology scores when compared to the other two groups of students who attended one Masters Camps and the control group, the results were not statistically significant. The results should encourage educational leaders to evaluate intervention programs being used in K-12. With the information from the study, educational leaders can allocate time, costs, and effort more efficiently as they make decisions about interventions expected to increase science and other state assessment scores. [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.]