Applied Behaviour Analysis is a science dedicated to the understanding and improvement of human behaviour. The science focuses on the identification of defined and observable behaviours of social significance. It provides us with the methods needed to identify target behaviours and to identify the antecedents (events that occur before the behaviour) and the consequence (events that happen after the behaviour). By changing the events around a specific behaviour, we can change the likelihood that the behaviour will happen again. Thus, Applied Behaviour Analysis allows us to teach new skills or behaviours and to increase or decrease target behaviours.

With respect to the communication, social and play deficits that exist in a child with autism, the principles of Applied Behaviour Analysis can be used to teach new skills and behaviours. Those same principles can be used to reduce certain inappropriate behaviours as well. It is through an individualized profile of child's skill deficits and behaviour excesses that an appropriate Treatment Plan can be delivered through the principles of Applied Behaviour Analysis.

A variety of teaching approaches have stemmed from the science of Applied Behaviour Analysis. They all have in common the use of data-driven procedures to ensure that teaching is effective. One particular approach, Discrete Trial Teaching, popularized by Dr. Ivar Lovaas, is used by the Centre for Early Autism Treatment in most early intervention programmes. However additional approaches derived from behaviour analytic principles are also used by CEAT when appropriate.