John was co-founder of Applied Psychology Services, the first independent psychology practice in the UK specialising in developmental disabilities. He was the originator of the STAR Approach, a system of analysing behaviour used in many services in the UK. John is a prolific writer. His books include Problem Behaviour & People with Severe Learning Disabilities: The STAR approach (1994); Behavioural Concerns & Autistic Spectrum Disorders (2000); Assessing Behaviours Regarded as Problematic for People with Developmental Disabilities (2002); People with Autism Behaving Badly: Helping people with ASD move on from behavioural and emotional challenges (2005). In addition, John has contributed chapters in many books and published numerous papers in peer- reviewed journals.