Psychology 2800E Lecture Notes - Lecture 8: Test Validity, Program Evaluation, Factorial Experiment

• School: Western University
• Department: Psychology
• Course: Psychology 2800E
• Professor: Doug Hazelwood

Document Summary

Chapter 11: true experiments part 2 factorial designs. Factorial design: 2+ variables are used in a way where all possible combinations are used. Independent variable is the variable that changes and dependent is the one being measured. Main effect: the effect of a variable averaged over all values of another independent variable. Interaction: when the effect of one independent variable depends on the level of another independent variable. Possible to have an interaction even if one independent variable has no main effect or even if neither iv have main effects. With a 2x2 factorial experiment you can get up to 8 combinations of results with data (based on individual main effects and interaction effects) Lines being parallel on a graph indicates the presence of an interaction whereas a dashed line indicates that there is no main effect. Types of interactions: antagonistic: interaction where the 2 independent variables tend to (cid:396)e(cid:448)e(cid:396)se ea(cid:272)h othe(cid:396)(cid:859)s effe(cid:272)ts (ex.