2- Within and Mixed Design ANOVA

Flashcards about Within and Mixed Design ANOVA based on lecture notes.

What is a within-subjects design also known as?

Repeated measures design/ANOVA

In a within-subjects design, do the same people take part in all possible levels of an independent variable?

Yes

What is a risk when controlling for individual differences in a within-subjects design?

Carryover effects

What assumption needs to be made in within-subjects ANOVA?

Sphericity

What is sphericity?

An assumption about variances where the differences between each pair of 'treatment levels' should have equal variance.

When is sphericity only important?

If a variable has three or more levels

What does violated sphericity lead to?

Increased risk of Type 1 error

What test assesses whether variances of the differences are equal?

Mauchley’s test

If the assumption of sphericity is violated, what happens to the degrees of freedom?

Corrections are made to degrees of freedom.

In adjusting degrees of freedom what is generally okay to use?

Greenhouse-Geisser

What are the components of Total Variability (SST)?

Between-participant variability (SSBetween) and Within- participant variability (SSW)

What are the components of Within-participant variability (SSW)?

Effects of the experiment (SSM) and Unexplained variability/error (SSR)

How is SSM calculated?

Same as a between-groups ANOVA

How is SSR calculated?

Subtract SSM from SSW

What is the formula to calculate Main effect df (SSM)?

a-1 (number of levels of Factor A-1)

What is the formula to calculate Error term df (SSR)?

(a-1)(s-1) (main effect df x subject df)

With Two-way within-subjects ANOVAs what does Within- participant variability break down into?

Effects of Factor A(SSA), Effects of Factor B (SSB), Interaction (SSAxB), and Unexplained variability/error (SSR)

What is a Mixed Design ANOVA?

An ANOVA that contains both between-groups and within-subjects independent variables

What assumptions need to be checked for regarding Mixed design ANOVA?

Equality of error variance in between-groups factors, Equality of variances across different levels of within-subjects factors, and Equality of covariances between within-subjects factors at each between-groups factor level

What are the tests to check assumptions for Mixed design ANOVA?

Levene’s test, Mauchley’s test, and Box’s M test