# PSY 311 Study Guide - Midterm Guide: Factorial Experiment, Statistical Significance, Analysis Of Variance

## Document Summary

Increasing the number of levels of an iv. In the simplest experimental design, there are only two levels of the iv: three or more can provide more information about the relationship. If a curvilinear relationship is predicted, at least three levels must be used. Factorial designs: experimental designs with more than one iv (or factor), the simplest is a 2 x 2 factorial design has two iv, each having two levels, this results in four experimental conditions. Interpretation of factorial designs: main effect the effect of an iv on a dv. Interaction situation in which the effect of one iv on the dv changes, depending on the level of another iv. Pv with at least two levels: see slide 12 for graph. Independent groups (between-subjects) requires the largest number of participants, as a different set of individuals is assigned to each condition.