12. Comparison of Several Means 4

Question 1

When are repeated measures designs used?

Answer 1

• same people exposed to different types of treatment

- same people exposed to one treatment and measured over time

Question 2

What are repeated measures assessing (differences)?

Answer 2

within-group, NOT between group

Question 3

assumptions of repeated measures

Answer 3

• normally distributed data
• DV measured at interval level
• sphericity

Question 4

sphericity

Answer 4

similar to homogeneity of variance in a between group ANOVA

Question 5

For sphericity to be an issue, what must be present?

Answer 5

need 3 conditions (ex. 3 different treatments, 3 different time periods)

Question 6

What is sphericity measured by?

Answer 6

Mauchly’s test

Question 7

Mauchly’s test = greater than 0.05

Answer 7

• significant

- assumption has been met

Question 8

Mauchly’s test = less than 0.05

Answer 8

• not significant

- assumption has been violated

Question 9

What happens if sphericity is violated?

Answer 9

can apply corrections

Question 10

What are the corrections to apply if sphericity is violated?

Answer 10

• Greenhouse-Geisser correction
• Huynh Feldt correction
• Bonferroni correction

Question 11

used if Mauchly’s test is less than 0.75

Answer 11

Greenhouse-Geisser correction

Question 12

used if Mauchly’s test is more than 0.75

Answer 12

Huynh Feldt correction

Question 13

Which is the best post hoc test to used if sphericity is violated?

Answer 13

Bonferroni correction

Question 14

f-stat for repeated measures: experiment effect

Answer 14

effect of the experiment shows up as within group variance vs between group

Question 15

for repeated measures f-stat, within-group variance is split into __ groups

Answer 15

2

Question 16

For repeated measures f-stat, what groups are within group variance split into?

Answer 16

• variance explained by the experiment

- unexplained variance - error

Question 17

What is a mixed design ANOVA?

Answer 17

• mixture of between group and within group variables

Question 18

between group variables

Answer 18

1 way ANOVA

Question 19

within group variables

Answer 19

repeated measures

Question 20

for a mixed design ANOVA, what must you have

Answer 20

at least 2 IVs

• 1 must include different participants (between group)
• 1 must include same participants (within group)

Question 21

Assumptions of a mixed design ANOVA

Answer 21

• normality of data
• DV at interval level
• independence (between group IV only)
• homogeneity of variance (between group IV only)
• sphericity (within group IV only if more than 3 conditions or time periods)

Question 22

f-stat for mixed design ANOVA

model sum of squares

Answer 22

broken down into within group and between group variance