This paper describes a scale for measuring "sense of community" efficiently and effectively in order to explore the relationship between online social networking group activities and sense of community. Scales developed to measure sense of community in prior research are usually lengthy and community specific. They are therefore not suitable or directly applicable to the context of our study in which we plan to use a virtual community to promote interdisciplinary research collaboration at a university. Our scale is relatively short, and exhibits good internal consistency at both the departmental level and the campus level. At the departmental level, this scale correlates with the number of tenure track faculty members that individuals are likely to list as friends or research colleagues. We discuss the use of our scale in future research.