In the previous chapter we referred to the need for observing and recording children's behaviour in an objective and systematic way. Human behaviour is notoriously difficult to observe because it happens in complex social situations which are also dynamic, that is to say, things are happening all the time. Classrooms are prime examples of such social situations. The purpose of this chapter is to enable you to identify key behaviours in certain children or groups of children by pinpointing them so that you will be able to judge precisely when they are happening and can record them accurately and objectively when necessary. In this chapter, then, we shall be looking at B, the behaviour, in the ABC model.