What child doesn't love marking somebody else's work? With a clear marking key, success criteria and purpose in mind, children set about assessing either their own, or a partner's piece of writing. Modelled through the teacher's own formative marking, pupils know what the expectations are. They are well trained in searching for successful examples of the learning intention, articulating their responses to the work, checking the writing matches any targets and giving constructive feedback. Seeing the children learn from each other in this way is hugely positive; you know you've done your job well.