Articles:Experimental and Quasi-Experimental Designs for Generalized Causal Inference: Chapter 1
From unthinkMedia
natural experiment: naturally-occurring contrast between a treatment and a comparison condition (Fagan,1990; Meyer, 1995;Zeisel,1,973)
quasi-experiments
- the cause is manipulable and occurs before the effect is measured.
- design features usually create less compelling support for counterfactual inferences
What they said
There are many natural social settings in which the research person can introduce some thing like experimental design into his scheduling of data collection procedures (e.g.,the when and to whom of measurement),even though he lacks the full control over the scheduling of experiment a stimuli (the when and to whom of exposure and the ability to randomize exposure which makes a true experimental possible. Collectively,such situations can be regarded as quasi-experimental designs
