Lecture 9: Moderation in ANOVA Flashcards
(23 cards)
What type of independent variables does ANOVA require?
Categorical
What statistical method is preferred when using continuous independent variables?
Regression
Why is it problematic to categorise continuous variables in ANOVA?
It causes information loss
What are the two components of variance in ANOVA?
Between-groups and within-groups variance
What does the F-ratio compare in ANOVA?
Systematic variance to error variance
What does the F-ratio indicate in hypothesis testing?
The presence of significant group differences
What does a main effect represent in factorial ANOVA?
The average effect of one factor
What does an interaction effect represent?
The effect of one IV depends on another IV
What does factorial ANOVA allow researchers to test?
Main and interaction effects
What statistical feature represents moderation in ANOVA?
Interaction effect
What does moderation imply about variable relationships?
One IV alters the effect of another IV
What graph feature indicates an interaction effect?
Non-parallel lines
Can an interaction exist without any main effects?
Yes
What does an omnibus test in ANOVA detect?
Any group differences
What is the purpose of follow-up tests?
To localise specific group differences
What tests are used for main effects follow-up?
Pairwise comparisons or linear contrasts
What is tested in a simple effects analysis?
The effect of one IV at each level of another
What type of error term is used in between-subjects follow-ups?
The omnibus test error term
What assumption is critical in within-subjects designs?
Sphericity
What test checks sphericity?
Mauchly’s test
What correction is used if sphericity is violated?
Greenhouse-Geisser
What statistical feature indicates moderation in ANOVA?
Interaction effect
Why are graphs recommended for interpreting interactions?
They make moderation visually intuitive
