Abstract: | SUMMARY. To assess the problems and needs of a disturbed child or adolescent, there should be an awareness of many interacting conceptual systems within which the individual exists and develops. This paper highlights the theoretical view that an individual cannot be fully understood within any single theoretical framework or system Using an awareness of the hierarchy of systems., formulations are set out to allow for logical interventions at one or more of these levels; thus reducing the need for professionals to decide on the ‘right’ intervention or treatment for any individual or family |