HST250H1 Lecture Notes - Lecture 9: John Stuart Mill, Confounding, Selection Bias
Document Summary
Lecture 9: observational research & experimental design: observe option. Randomized, control trials: key elements in experimental design. Dependent variable: key elements in experimental design. Control variable: variables that are known to influence outcome. Intervening variable: variables that modify the relationship between independent and dependent variable. Confounding variable: external variables that may cause the observed relationship between independent and dependent variable. Presumed extraneous variables: vary without control but are taken into consideration: rationale of the experiment. Developed by john stuart mill in the method of difference . A well-designed experiment should provide clear evidence of a cause-effect relationship. Indicate whether the independent/treatment variable actually bring about change in the dependent variable. Look for differences in results, not similarities: basic types of comparisons. Between subjects: comparison of effects among people of similarities. Within subjects: comparison of effects among people with different characteristics: to demonstrate a causal relationship. Changes in treatment variable occur prior to changes in dependent variable.
