This chapter presents a classification of social learning mechanisms and explains how these mechanisms can be distinguished empirically. In most published social learning studies it is very difficult to determine exactly which mechanisms are operating. This is because experiments are often not designed with this primary purpose. Nonetheless, in such cases a researcher may still wish to draw some inferences about the process underlying a particular case of social learning. The chapter discusses stimulus enhancement, local enhancement, observational conditioning, response facilitation, social facilitation, imitation, observational R-S learning, emulation, opportunity providing, inadvertent coaching, and production imitation. It also considers a pragmatic approach to characterizing mechanisms of social transmission.