PSYC 217 Lecture Notes - Lecture 9: Repeated Measures Design, Random Assignment, Dependent And Independent Variables
19 Feb 2016
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Cause and effect- experimental sometimes researchers conduct both. Experimental control or random assignment- method of keeping variables constant. If scores of groups differ, researcher can conclude the independent variable caused results b/c the only difference is the manipulated iv. Confounding variable- varies along with the independent variable, confounding occurs when the effects of the independent variable and uncontrolled(dv) are intervened in a way that you cant tell which variable cause results. In a good casual experiment there shouldn"t be competing alternative explanations. High internal validity- when in a experiment the only variable responsible for the results is the independent variable. List and explain 3 major steps toward planning a basic experiment: Obtain two equivalent groups of participants- assigning them to levels of independent variables. Must be equivalent to avoid selection differences- pole selected cannot differ in any systematic way ex. if you select high income class for a group the others in the other group must be high income class.
