Factorial Design

main effect

the impact of a single variable on what we are measuring

interaction

combined impact of two main effects on what we are measuring

lines that cross on interaction graphs indicate an ___ __while lines that run parallel indicate ___ likelihood of an interaction__

interaction, less

if we state that there is no main effect, then the independent variable did NOT have an effect on the outcome, or was not signficiant.

true

cell mean

the average on the dependent variable for participants with a specific combination fo the levels of the independent variables

marginal mean

the average of all participants on one level of the independent variable, ignoring other independent variables

suppression effect

an effect where two variables combine to produce an outcome that is smaller than what each indivdiual variable contributes

synergistic effect

an effect where two variables combine to produce an outcome that is greater than what each individual variable contributes

two-way analysis of variance

a statistical test that allows us to simultaneously test how two separate nominal or categorical independent variables (or factors) influence the dependent variabe, and how those independent variables interact to influence the dependent variable; also known as a two-way ANOVA or factorial ANOVA

a factorial design requires a minimum of how many independent variables?

2