ABC The letters ABC stand for antecedents, behaviour and consequences. The ABC is a method for recording specific, overt and observable behaviours. It is a method based on behavioural psychology. An ABC identifies the antecedents and consequences of specific and overt target behaviours. Antecedents are observable events occurring immediately before the target behaviour, and consequences are events occurring immediately afterwards. The target behaviour can be any behaviour such as that manifested in EBD or LD. It forms the basis for a functional analysis of behaviour.