This article reviews the origins and use of the terms quasi-experiment and natural experiment. It demonstrates how the terms conflate whether variation in the independent variable of interest falls short of random with whether researchers find, rather than intervene to create, that variation. Using the lens of assignment--the process driving…

Randomized experiments are a strong design for establishing impact evidence because the random assignment mechanism theoretically allows confidence in attributing group differences to the intervention. Growth of randomized experiments within educational studies has been widely documented. However, randomized experiments within education have…

There has been increased focus within the evaluation field on the value of community-engaged research (CER) methods; however, CER is not easily seen as compatible with experimental evaluation methods (or randomized controlled trial, RCT). For instance, in an experimental design, researchers leverage randomization to create a counterfactual; this…

By design, randomized experiments (XPs) rule out bias from confounded selection of participants into conditions. Quasi-experiments (QEs) are often considered second-best because they do not share this benefit. However, when results from XPs are used to generalize causal impacts, the benefit from unconfounded selection into conditions may be offset…