Just because we teach our students something, doesn’t mean they have learned it. Believing in this input/output myth leads to mistaking performance for learning. The fact that students are able do something at the end of one lesson (i.e. perform) is due to a short-term chemical change in the brain and does not mean they will be able to do it next lesson. As a consequence, we believe that learning is the long-term retention of skills and knowledge that can be applied to a new context, and happens when the structure of the brain physically changes, rather than just chemically. At New College we talk about teaching for learning: teaching that supports learning by altering the physical structure of the brain by changing and increasing the connections between neurons. This necessitates the interplay between the creation of high challenge, low threat learning environments, deep teacher subject knowledge, the use of research-informed pedagogy, and frequent assessment and feedback (see our Teaching for Learning Framework).