Why an Active Control Group Makes a Difference and What to Do About It

Abstract

The Randomized Control Trials (RCT) design and its quasi-experimental kissing cousin, the Comparison Group Trials (CGT), are golden to some and not even silver to others. At the center of the affection, at the vortex of the discomfort, are beliefs about what it takes to establish causality. These designs are considered primarily when the purpose of the evaluation is establishing whether there are outcomes associated with a program and, if so, how confidently the results can be attributed to the program. If one concludes these designs are superior to alternatives for establishing causality, and have no more bad habits than the alternatives, then the RCT and the CGT are the methods of choice.