This paper uses theory from sociology of education to explore associations between mentors' and senior colleagues' perceptions of schoolwide collective responsibility and the frequency of their interactions with novice teachers. Survey data was collected from novice teachers, their mentors, and their school-based colleagues in 6 Michigan districts and 5 Indiana districts in 2007-2008. The findings suggest that mentors' perceptions of collective responsibility for learning are strongly associated with their interactions with mentees, and that senior colleagues' perceptions of schoolwide collective responsibility are also critical to their interactions with novice teachers. This study has implications for principals' efforts to facilitate interactions between beginning teachers and their mentors and colleagues about core instructional issues.