Focusing on the rights, responsibility, and role of one who intervenes therapeutically in another person's life, this volume builds on a practical and theoretical human relations base with a view toward guidelines for effective professional training and personnel selection. In an overview of the helping profession, the first chapter presents evidence that lay training programs have been more effective than professional programs as measured by indexes of constructive change in those helped. Part 2 provides a paradigm for the development of psychological health and psychopathology and analyzes variables (helper, helpee, contextual and environmental influences) that influence the success of treatment programs. The next two sections discuss the creation of selection and training procedures, with particular emphasis on the need for skills in discrimination (ability to choose the most suitable helping procedure) as well as in communication or empathy. Finally, a selection and training model is proposed which offers a formula for predicting effects of training on the level of trainee functioning. (LY)