Chapter 14: Repeated Measures Designs

Question 1

compound symmetry

Answer 1

a condition that holds true when both the variances across conditions are equal and the covariances between pairs of conditions are also equal

Question 2

Greenhouse-Geisser Estimate

Answer 2

• an estimate of the departure from sphericity
• the max value = 1 (completely meets sphericity) and the minnimum is the lower bound
• values below 1 indicated departures from sphericity and are used to correct the degrees of freedom associated with corresponding F-ratios by multiplying them by the value of the estimate
• too conservative (strict)

Question 3

Huynh-Feldt Estimate

Answer 3

• estimate of the departure of sphericity
• max value = 1 (completely meets sphericity) and values below this indicated departures from sphericity and are used to correct the degrees of freedom associated witht he corresponding F-ratios by multiplying them by the value of the estimate
• Too Liberal

Question 4

Lower Bound Estimate

Answer 4

name given to the lowest possible value of the Greenhouse-Geisser estimate of sphericity

value = 1/(k-1) where k is the number of treatment groups

Question 5

Mauchley’s Test

Answer 5

tests the hypothesis that the variances of differences between conditions are equal
if significant < .05 then sphericity is not met!

Question 6

Repeated-Measures ANOVA

Answer 6

an alalysis of variance conducted on any design in which the independent variable (predictor) or variables (predictors) have all been measured using the same participants in all conditions

Question 7

Sphericity

Answer 7

assumes that the variances of the differences between data taken from the same participant are equal

the assumption is most commonly found in repeated-measures ANOVA, but applies only where there are more than two points of data from the same participant