In a growing body of literature, education researchers are applying social network theory to study teacher learning and school improvement (Spillane, Hopkins, & Sweet, 2014). Theory and empirical research suggest that teachers' professional ties, and the social capital that such ties enable, influence teachers' learning, instructional improvement, and the success with which reforms take hold in schools (e.g., Atteberry & Bryk, 2010; Bryk & Schneider, 2002). While social capital can take on a variety of forms, the term generally refers to the potential for individuals to "secure benefits by virtue of membership in social networks or other social structures" (Portes, 1998, p. 6). Such benefits may come through the flow of information or material resources, obligations and expectations, trust, or norms and sanctions. In education, researchers have shown the importance of teachers' social capital for numerous outcomes, including the success of instructional reform efforts