Treatment Validity for Intervention Studies

That psychologists conduct sound research is important whatever their research areas, but it is especially important when the results of this research have a substantial impact on people’s lives. This is the case for intervention research, the findings of which may influence the type of treatments people receive. Sound intervention research is critical for determining what treatments are beneficial and what treatments are ineffective or even harmful. Moreover, intervention research is typically very expensive to conduct, with a single project often taking 5 to 7 years to complete and costing well over $1 million. This means that relatively little psychosocial intervention research is conducted, making the validity of each trial that much more important. Intervention research is challenging, and during such a study (often called a trial), investigators will be faced with many uncontrollable events they could not have foreseen. Common problems in treatment research are predictable, however, and many potential difficulties in interpretation of findings can be avoided with proper attention to design before the trial begins. In this chapter we will review the most common design questions in intervention research and will specify the basic elements we believe must be present to permit researchers to draw valid conclusions from their data.