As part of the general move towards accreditation and greater professionalism, practice teachers (supervisors) have to be accredited and undergo some training and practice teaching. This handbook, commissioned by the North of Scotland Consortium for Education and Training provides the theoretical base that practice teachers need. It provides a summary of the theory underlying models of understanding human development and behaviour, and of models of social work intervention. Because of its combination of theory and practice it will be of equal use to social students and practitioners and practice teachers supervising students under the new Diploma in Social Work programme.