Supporting Computational Algorithmic Thinking (SCAT) is a longitudinal between-subjects research project exploring how African-American middle-school girls develop computational algorithmic thinking (SCAT) capabilities over time in the context of game design. SCAT is also a free enrichment program designed to expose middle school girls to game design. The goals are: 1) to explore the development of computational algorithmic thinking over three years in African-American middle-school girls as they engage in iterative game design, and 2) to increase the awareness of participants to the broad applicability of computational algorithmic thinking across a number of industries and career paths. Spanning three years, participants, called SCAT Scholars, develop CAT capabilities as they design more and more complex games. SCAT Scholars begin the program the summer prior to their 6th grade year and continue through their 8th grade year. They engage in 3 types of activities each year: 1) a two-week intensive game design summer camp; 2) twelve technical workshops where Scholars implement the games they have designed using visual and programming languages (e.g., SCRATCH, GameMaker, GameSalad) in preparation for submission to national game design competitions (e.g., National STEM Video Game Challenge); and 3) field trips where Scholars learn about applications of CAT in different industries and careers.