PSY309H1 Chapter Notes - Chapter 8: Confounding, Internal Validity, Dependent And Independent Variables
Document Summary
Confounding variable a variable that varies along with the independent variable and therefore not controlled. Confounding occurs when the effects of the independent variable and an uncontrolled variable are intertwined so the variables responsible for the observed effect cannot be determined. Good experimental design involves eliminating possible confounding that results in alternate explanations. Internal validity the certainty with which results of an experiment can be attributed to the manipulation of the independent variable rather than to some other, confounding variable. To achieve internal validity, the researchers must design and conduct the experiment so that only the independent variable can be the cause of the results. The simplest experimental design has two variables: independent variables and dependent variables. The independent variable has two levels: experimental group and control group. The simplest experimental design can take two forms: posttest-only design or pretest-posttest design.
