An introduction to the use of randomized control trials to evaluate development interventions

RCTs have become popular in the development community as part of the response to the results agenda. These studies are well placed to address the question of which programmes work or not. And, properly designed, they can be embedded in a broader evaluation design which also addresses questions of why an intervention works in a specific context or not, and at what cost. Usually the appropriate design will not be a simple randomization drawn from an eligible list. So there are several decisions to be made in designing a RCT, and these decisions should be recorded in a study protocol which is placed in the public domain before the study begins. Many of the criticisms of RCTs can be responded to. But some require more reflection and research and have implications for the conduct of RCTs.