This publication discusses the topic of rigorous impact evaluations. “Rigorous impact evaluations are useful for determining the effects of USAID programs on outcomes. This type of evaluation allows managers to test development hypotheses by comparing changes in one or more specific outcomes to changes that occur in the absence of the program.” This document was published by USAID in 2010. It is one of a series of TIPS that provide practical advice and suggestions related to performance monitoring and evaluation.