Research interests are in the conceptual, applied and experimental analysis of behaviour, with the emphasis currently on conceptual and applied aspects. Conceptual work has focussed on two long-term projects. One project has involved developing a bio-behavioural model of the processes which engender, maintain and reverse infant sleep disturbance. The second project has been to view the current widespread criticism of null-hypothesis statistical tests and other standard research practices from the perspective of single-case research design. Applied research has a wider focus, and includes behavioural interventions for infant sleep disturbances, behavioural family therapies, special education interventions, and various projects in Health Psychology, including a specific interest in safety, especially road safety.