When most of us were at school failure was seen as something that was negative, should be avoided and often worth punishment. And yet most learning theorists agree that it is only through failure that we really learn – as opposed to just memorising. Failure is useful when it helps us critically appraise our own performance. This is evaluation is an example of feedback. A simple way to think of feedback is experiencing the output of your own performance as a new input.

Students of psychology and education are becoming increasingly aware of the vital role that feedback plays in how we learn. All complex systems (like your body, your organisation, your family, your community) change their behaviour or learn through feedback - even if this means weaving in and out of the best path (like Wiener’s boat example) rather than sticking to the best path in any strict way.