Experimental and quasi-experimental study designs primarily stem from the positivism research paradigms, which argue that there is an objective truth to reality that can be discerned using the scientific method.1 This hypothetico-deductive scientific model is a circular process that begins with a literature review to build testable hypotheses, experimental design that manipulates some variables and controls others, and then careful assessment and analysis of those effects to build further theories and experiments, before cycling through again. In 1963, Campbell and Stanley2 categorically defined experimental education research as 鈥渢hat portion of research in which variables are manipulated and their effects upon other variables observed鈥�p1 and quasi-experimental as education research 鈥渨here random assignment to equivalent groups is not possible.鈥�p2 Surgical education studies frequently must forego true randomization due to factors outside the researcher鈥檚 control. For example, medical students doing their surgery clerkship at the end of the year are not identical to the medical students on their surgical clerkship as their first rotation of the academic year. Therefore, for the rest of this guide, we will refer to both experimental and quasi-experimental study designs as experiments.