Collaborative group work plays an important part in postsecondary education, and the ability to assess the quality of such group work is useful for both students and instructors. The purpose of this study was to develop a self-report measure of students' perceptions of the quality of their interactions during collaborative educational tasks. Collaborative interactions were operationalized using the construct of heedful interrelating, which is interacting with sensitivity to the task at hand while at the same time paying attention to how one's actions affect overall group functioning. In Study 1 (N = 111 undergraduates; M[subscript age] = 20.3 years; 78% female) both factor stability, assessed using exploratory and confirmatory factor analytic techniques, and convergent validity were established for the six-item Heedful Interrelating in Collaborative Educational Settings (HICES) scale. In Study 2 (N = 147 undergraduates; M[subscript age] = 20.5 years; 82% females) the HICES scale's factor structure was further supported via acceptable model fit of cross-validating sample, and predictive validity was established in terms of the HICES scale's positive relationship with performance. The results of these studies support the reliability and validity of the six-item HICES scale. Implications for use of the HICES scale in research and practice are discussed.