Clinical reasoning is 'a skill, process, or outcome wherein clinicians observe, collect, and interpret data to diagnose and treat patients' (Daniel et al, 2019). It is complex and takes years to learn. Studies show diagnosis frequently goes wrong, and it is the most common, costly, and dangerous of medical mistakes.  As a result, there is a growing consensus that medical schools and postgraduate training programmes need to teach clinical reasoning in a way that is much more explicit, systematic and consistent with evidence from the learning sciences.