There are legitimate barriers to implementing effectively in schools – the bombardment of new ideas and initiatives, limited time and resources, and the pressure to yield quick results, to name just a few. Nevertheless, this guidance report shows a lot can be achieved with careful thought, planning, and delivery using existing resources and structures. It is about making the implicit explicit, providing clarity and purpose to existing processes, and reframing what you are already doing, rather than bolting on a whole new set of procedures. The guide can be used to help implement any school improvement decision, whether programme or practice, whole-school or targeted approach, or internal or externally generated ideas. Over the last few years, the Education Endowment Foundation (EEF) has developed an approach to evidenceinformed school improvement, which treats the school as a continuously improving system. The model aims to frame research evidence in a school’s context, rather than the other way around, integrating the best available external evidence with professional expertise and internal data. The cycle has five steps: 1. Decide what you want to achieve. 2. Identify possible solutions and strategies. 3. Give the idea the best chance of success. 4. Did it work? 5. Secure and spread change. We suggest schools use this implementation guide as part of an overall advance towards evidence-informed school improvement. This guide covers all of the steps briefly, but focuses mainly on Step 3, ‘Giving an idea the best chance of success’. The EEF has a range of additional resources to support schools across the other steps of this process, for example, the Families of Schools database (Step 1), the Teaching and Learning Toolkit (Step 2), and the DIY Evaluation Guide (Step 4).