This study examines how to investigate traditionally underrepresented students' sense of belonging, self-efficacy, and academic engagement in science, technology, engineering, and mathematics (STEM) residential learning communities (RLCs). A 28-item survey was developed that included items from three previously validated instruments to measure three constructs: academic engagement; self-efficacy; and sense of belonging to the academic major, institution, and residential community. The survey was administered to first-year residential students pursuing a STEM major at three universities. This article discusses the development and administration of a survey to measure these constructs and the resulting validity scores. Samples included students living in STEM RLCs and STEM students not living in RLCs. An exploratory factor analysis examined validity, and Cronbach's alpha was computed for internal consistency. Belonging to the university, belonging to academic major, and belonging to residential learning community emerged as separate factors, indicating that students appear to conceptualize these different types of belonging during their college experiences. These constructs can be used to explore differences between student populations. Despite the small sample sizes, there were observations suggesting that differences in sense of belonging, academic engagement, and self-efficacy exist between traditionally represented and underrepresented students. However, further research is needed to explore these questions.