8 Quasi-Experimental Design and Methods
Quasi-experimental research designs, like experimental designs, test causal hypotheses. Quasi-experimental designs identify a comparison group that is as similar as possible to the intervention group in terms of baseline (pre-intervention) characteristics. The comparison group captures what would have been the outcomes if the programme/policy had not been implemented (i.e., the counterfactual). The key difference between an experimental and quasi-experimental design is that the latter lacks random assignment.