POLSCI 3N06 Lecture Notes - Internal Validity, Stratified Sampling, Cluster Sampling
21 Nov 2013
School
Department
Course
Professor
Document Summary
Pre & post- testing methods to examine degrees of change in political" orientations. Internal validity would be ensured through use of control and experimental groups. Ensuring external validity through a large enough group that is representative of the larger population; In the united states we would be using stratified sampling or cluster sampling. No other factors are affecting except internal validity: confounding, maturation (length of experiment, selection bias, experimental bias (the participants know what you are looking for, so they give it to you) Reactivity (experimental bias and people"s interactions with each other, it will affect the response: history, regression when people are exposed to confounding variables even if are controlled, but experiences with similar experiences tend to get extrapolated; People dropping out of the experiment and having to replace them with someone else; There is a big trade off between external and internal.
