Collaboration is now the name of the game. Increasing complexity and the pace of change facing education systems have led to increased demands around teachers' practice and professionalism. Developing professional learning communities (PLCs) or networks does not happen by itself; it needs the energy and influence of leadership. Collaboration can be found in a policy focus on partnership working between schools to develop what has been described as a self-improving school system. Alongside the emphasis on collaboration, a thrust has been towards developing teaching as an evidence-based profession. Middle leaders learnt research-informed approaches to tracking impact - an essential feature of professional learning communities - and enabled others to do the same. Most middle leaders' initial knowledge about tracking impact was superficial and tacit. Research Learning Communities (RLCs) have evolved from the literature on PLCs and networked learning communities (NLCs). RLCs, however, were designed with the specific purpose of increasing research use in schools at scale.