The phrase "knowledge adoption" refers to the often-complicated process by which policy makers "take on board" evidence. While models have been put forward to explain this activity, this paper argues that such models are flawed and fail to fully address those complexities affecting the successful realisation of knowledge adoption efforts. Existing frameworks are examined, critiqued and an alternative, sociologically based approach presented. It is argued that this alternative conceptualisation provides a more effective account of the knowledge adoption process. The paper illustrates how this model has been tested and examines its implications for both research impact and evidence-informed policy making.