The clinician is deeply concerned with the difficulties of selecting a treatment method that will accomplish the goals which he wishes to achieve for a particular patient with specific symptoms and characteristics in a particular treatment setting, knowing that it is unlikely that any one single treatment will be universally and equally effective in all situations. The research investigator should attempt to help him by furnishing objective evidence as to the specific efficacies and limitations of methods of treatment in common use under the conditions that prevail where large numbers of patients are treated—in public mental hospitals. Adequate comparative information obtained under controlled experimental conditions is essential not only to therapists but also to patients and their families and to those responsible for the support and administration of treatment centres.