Bandura's research on observational learning laid the foundation of role model research. Contemporary research shows role models support women and racial/ethnic minority students in STEM by buffering them from the deleterious effects of stereotype threats and boosting their self-efficacy. However, certain characteristics can make role models more or less influential. Thus, it is important to understand "when" and "how" role models influence minoritized students' motivation in STEM. In this article, we (a) review Bandura's theory of observational learning and its links to role modeling, (b) discuss the characteristics and mechanism of role models, and (c) make 3 recommendations for promoting the effectiveness of role models as an important way to diversify STEM.