In this report, Ferguson evaluated the impact of a weekly chess club intervention, lasting 32 weeks, on grade 7-9 gifted and talented students’ cognitive development, measured by the Watson Glaser Critical Thinking Appraisal and the Torrance Tests of Creative Thinking. The sample included 15 treatment students and 79 control students in a northern Pennsylvanian school district. Students self-selected to participate in intervention, and control group students had a statistically insignificant higher average IQ. Ferguson uses tests of statistical significance to determine if treatment students’ observed gains are significantly higher than control students’ gains. The author found an effect size of 0.782 standard deviation units. The results were statistically significant. The study was eligible for inclusion in the systematic literature review and categorized as a Tier III study. A simple comparison of relative gains on the assessments between treatment and control students, without controlling for other variables, does not account for other factors that may confound the findings. Because the study focuses on gifted and talented students, results may not be generalizable to other student populations.