POLS 2503 Lecture Notes - Lecture 8: Internal Validity, Design Of Experiments, Treatment And Control Groups
24 Oct 2017
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Document Summary
Experiments are internally valid because they show a direct link between cause and effect. Experimental design is the gold standard of research design: explanatory, low external validity low generalizability, causality easy to assess causation, closest to truth. Steps of experimental research: ensure sample is a valid representation of the population via random selection. (external validity) 2: randomly assign individuals to a group. (internal validity, provide treatment. (internal validity) Review: treatment group receives the independent variable, control group does not, randomization prevents selection bias, omitted variable bias, intervening variables and ensures functionally equivalent groups.
