Representations of practice provide an opportunity to refer to teachers’ professional environment both when designing tasks for teacher education or professional development, and when investigating aspects of teacher expertise. This volume amalgamates contributions by the members of the discussion group on representations of practice, which took place during ICME 13. The discussion group sought to collect experiences with different forms of representations of practice in pre-service and in-service teacher professional development settings, and of the use of representations of practice for researching into aspects of teacher expertise and its development. In this introductory chapter we provide an overview of different approaches to representing practice, and address key methodological issues that came up in the monograph’s chapters and in the discussion group’s meetings. We suggest four key questions along which such approaches can be discussed.