The attrition of students belonging to populations traditionally a minority in STEM disciplines remains a national priority for undergraduate education. Arguably a critical inflection point for many college students is their first exposure to a STEM discipline that occurs in large entry-level survey courses. In these courses student inquiry is often negligible with many students uncomfortable posing verbal questions, stemming in part from a lack of confidence, fear of looking foolish and discomfort in disrupting the class, and is particularly pronounced for students traditionally underrepresented in STEM fields. Accordingly, such climatic factors are considered critical to addressing STEM college student attrition. A relatively novel approach to addressing large-class climatic features is the use of in-class anonymous "backchannels" as a 'social layer' to improve student classroom engagement. This roundtable will present and discuss the educational foundations for the use of backchannels in large courses and results from the NSF study. Participants will learn the benefits and challenges of including a backchannel in class and how they can conduct a study of backchannels in their own classes.