STATS 13 Lecture Notes - Lecture 1: Dependent And Independent Variables, Observational Study
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We will now start to focus on research questions comparing two groups. When comparing two groups, there are two variables. Determine if there"s an association between the two variables. Determine if a cause-and-effect conclusion is permitted. Explanatory variable (independent, predictor, x-variable): explaining the change. Response variable (dependent, outcome, y-variable): variable being impacted or changed by the explanatory variable. Two variables are associated if one variable gives us information about the other variable. Observational study: the subjects in the study are simply observed. Observational studies may have confounding variables present that prevent us from determining a cause and effect. Experiment: the researcher/experimenter manipulates the treatment variable and assigns the subjects to those treatments at random. Treatment variable is another word for explanatory variable. Causal relationship are possible with an experiment. We are interested in studying the effectiveness of a vaccine for this year"s flu. We take a random sample of 100 people.
