“…To determine program effectiveness while controlling for self-selection, matched sampling attempts to overcome the confounding that may occur when initial group differences are not controlled for (Campbell and Stanley, 1967) and provides an approach that is close to true experimental randomization (Stuart and Rubin, 2008), which might offer the most confidence in making conclusions about the effect of the program on student outcomes. Many studies we reviewed in our literature search compared results with a matched sample of similar students based on some operationalization of STEM preparedness, such as standardized test scores or high school performance (e.g., Gilmer, 2007;Bradford et al, 2019). Other studies used nonbridge underrepresented minority STEM students, or in the broadest cases, all other STEM students, as control group students (e.g., Kopec and Blair, 2014).…”