Experiments versus quasi-experiments: do they yield the same answer?
Shadish
W R
WR
Department of Psychology Memphis State University, TN 38152, USA.
Heinsman
D T
DT
D006801:Humans; D008962:Models, Theoretical; D011897:Random Allocation; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data; D012107:Research Design; D019966:Substance-Related Disorders / Q000517:prevention & control