PSYC 217 Chapter Notes - Chapter 8: Confounding, Repeated Measures Design, Internal Validity
Document Summary
Learning objectives: describe how confounding variables affect the internal validity of an experiment. A confounding variable is something that is not kept constant between conditions. It is intertwined with the iv and you don"t know which is causing the change in your dv. Independent group design: participants are randomly assigned to each level of the iv. i. Completely up to chance who goes in what condition. Repeated measures design: when all individuals participate in all levels of the experiment. Advantages of this design is you need fewer participants and it is sensitive to statistical change: random error groups differ due to individuals differences and not because of the manipulation, disadvantages are the: Order effect : the order in which you present the testing affects the dependent variable. Practice effect: improvement in performance due to repeated practice in the test. Fatigue effect: deterioration in performance due to getting tired or bored with the tests.
