Alongside many examples of highly effective practice, there are numerous studies showing ineffective practice. These studies suggest substantial improvements in efficiency are possible, meaning considerably more could be achieved for the same budget. Other fields, such as medicine and aviation, have shown how large improvements can be achieved through collecting and applying evidence effectively. A number of barriers hinder more effective practice, such as the challenges of accessing appropriate information and evidence complacency, where evidence is not sought despite being available. This chapter thus outlines the problems: the subsequent chapters provide the solutions.