POS 3713 Chapter Notes - Chapter 4: Asteroid Family, Data Set, Random Assignment
1 Mar 2017
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4. 1 comparison as the key to establishing causal relationships. Research designs: strategies that help scientists determine whether x causes y. 2 most common and e ective designs: experiments and observational studies. Experiment: a research design in which the researcher both controls and randomly assigns values of the independent variable to the participants. Control: the values of the independent variable that the participants receive are not determined either by the participants themselves or by nature. Random assignment: assigning participants randomly using a coin toss, drawing numbers out of a hat, random-number generator, etc. Treatment group: group who will see the negative ad. Control group: group will will not see the ad, but will instead watch something innocuous, in a social science parallel to a placebo. Systematically di erent: the simple comparison in a non-experiment between those who do and do not see the ad is potentially misleading because it is confounded by other factors like interest in politics.
