In this chapter, I am going to take the vexed question of assessment and expand its usual field of reference so that I will discuss not only assessment for learning, but also describe its use as an instrument which provides information that enables the leadership teams in a school to monitor whether all students are encountering, regularly, that range of situations which enables deep learning. I believe that learning is social, that learning to learn is at the heart of education, and that currently, assessment focuses on too narrow a range of memorised outcomes and simplistic information sources.