Within-Subjects ANOVA

Question 1

What is an asymmetric carry-over effect?

Answer 1

Worrying that doing the study A > B or B > A will produce different effects.

Question 2

What is an assumption of sphericity?

Answer 2

An assumption about variances.

Difference between levels should have the equal variance.

Only important if there are 3 or more levels.

Question 3

What can violated sphericity increase?

Answer 3

Risk of Type 1 error

Question 4

What are the 4 assumptions of within-subjects ANOVA?

Answer 4

1. Data is ratio or interval (continuous)
2. Normal distributions
3. Independence of data
4. Sphericity

Question 5

What can the total variability be explained by?

Answer 5

Variance explained by our manipulation + variance not explained by our manipulations

Question 6

What are the 2 things that make up the variance not explained by our manipulation?

Answer 6

1. Individual differences
2. Experimental error

Question 7

What does the residual error show?

Answer 7

How much of our variance is due to experimental error.

Question 8

How to work out residual error?

Answer 8

Overall within-subject variability - subject variability

Question 9

What 3 types of degrees of freedom do we need to calculate?

Answer 9

1. Main effect
2. Subject
3. Error-term

Question 10

What result means that sphericity hasn’t been violated in Mauchley’s test of sphericity?

Answer 10

0.05 or above.

Question 10

What result means that sphericity hasn’t been violated in Mauchley’s test of sphericity?

Answer 10

0.05 or above.

Question 11

What correction for sphericity do you choose?

Answer 11

Greenhouse-Geiser