Our study investigates how research-based instructional strategies spread  among departments, using the example of Student-Centered Active Learning Environment for Undergraduate Programs (SCALE-UP). We are interested in how instructors learn about and implement SCALE-UP in different academic disciplines. Based on a web-based survey of 564 college and university faculty we use social network analysis (SNA) to quantify and map the interactions of instructors, departments and institutions as they share information about the SCALE-UP instructional strategy. SNA allows us to examine the underlying structure of the SCALE-UP network as well as single out influential actors. We used a set of nonparametric multiple regression techniques to evaluate the influence of actors' attributes on their role in the SCALE-UP network, and any structural features between actors that could predict their interactions. Results indicate that the majority of participants learned about SCALE-UP through the attendance of workshops or talks and personal interactions with colleagues, followed by reading literature or the Internet and using the SCALE-UP website. The SCALE-UP network contains few very influential nodes, with many outgoing ties. Similarities in gender and academic rank did not lead to an increase in interactions about SCALE-UP. In contrast, we found that institutional and departmental proximity between instructors increased the rate of interaction about SCALE-UP. Personal attributes such as gender, teaching experience, SCALE-UP user status and disciplinary affiliation showed no effect on instructors' role or status in the network.