Quasi-experimental

From EvaluationWiki

A research design that does not involve random allocation of subjects between control and experimental groups, but approximates that design (see RCT) in other respects, e.g., using a comparison group that is matched on all apparently relevant characteristics. The term, due to Campbell and Cook, is misleading because it suggests that these designs are less adequate for establishing causal connections, when in fact they are often just as adequate, and often have other huge advantages (e.g., reduced cost, shorter timelines, less ethical problems). The key error here is to think that 'adequacy' involves some standard that goes beyond the scientific and legal requirement of 'beyond reasonable doubt' which can readily be obtained by other designs (see RCT).