An integral part of true formative assessment is what teachers and students do after taking an assessment to improve student understanding of the topic. However, there are no research-based best practices for what types of activities work best in this intervention phase of formative assessment for the secondary social studies classroom. This research study addresses that issue through a quasi-experimental method to examine the effects of two types of interventions suggested by the literature, teacher-directed assignments and student self-assessments, in a secondary social studies setting. In addition, a mixed-methods case study was conducted to identify other factors within the classroom setting that may have impacted the effectiveness of these intervention methods. This study was conducted on ninety-two high school juniors, across four US History classes in a suburban high school in the upstate of South Carolina, USA. The data from the quasi-experimental portion of the study was analyzed by calculating the changes in scores between a formative assessment and a summative test over six units of study. The means of these changes were first analyzed by unit through single-tailed t-tests and then through a linear mixed model. The results showed an improved performance among college prep students via student self-assessment interventions, however these failed to meet the threshold of statistical significance. Some results did meet statistical significance which showed teacher-directed activities had a greater positive impact among honors students. The case study data came from teacher and student surveys and interviews. These were analyzed through correlations and coding based on grounded theory. From these analyses, the researcher concluded that student attitudes towards the individual interventions and the beliefs they held about the assessments may have had important impacts on their effectiveness. [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.]