A programmatic approach to socially complex intervention development

First used in psychiatry to study pharmacological treatments, the randomized controlled trial provides the most powerful test of the relative effectiveness of two or more interventions. Applying RCT methodology to socially complex service interventions, however, presents unique challenges that derive from difficulties in treatment standardization, attaining study sample equivalence and controlling for environmental variations. These challenges can be managed when intervention development proceeds along a programmatic trajectory that spans discovery, development, efficacy, effectiveness and practice research. Copyright © 2000 John Wiley & Sons, Ltd.