Repeated-Measures ANOVA Flashcards
Chapter 10-12
What is a Repeated-Measures ANOVA?
a specific type of ANOVA that is used to evaluate the mean differences in a research study comparing two or more conditions using the same sample of individuals in each condition
What are the advantages of repeated-measures designs?
- require fewer participants
- suited for studying change over time (pre-post design)
- reduces problems caused by individual differences
What is Stage 1 of partitioning of variance in repeated-measures ANOVA?
- between-treatments variance
- within-treatments variance
What does between-treatments variance represent?
- amount of systematic differences due to a treatment effect
- amount of unsystematic differences due to error or chance
What does within-treatments variance represent?
- variability due to individual differences
- differences due to other sources of error
What is Stage 2 of partitioning of variance in repeated-measures ANOVA?
variability due to individual differences (between-subjects variance) is removed from within-treatments variance
What does between-subjects variance represent?
variance within-treatments due to individual differences
What does error/residual variance represent?
variability that is residual or leftover after removing the effects of individual differences reflecting variability that is due to error or chance
What is the difference between the denominator of one-way ANOVA and repeated-measures ANOVA?
individual differences are a part of one-way ANOVA F-ratio but are eliminated from the repeated-measures F-ratio
What is eta-squared?
percentage or proportion of variance in the dependent variable that is accounted for by the condition effect
What are the assumptions of repeated-measures ANOVA?
- populations from which are selected must be normally distributed
- sphericity
What is sphericity?
equal variances across differences scores
When do you conduct a post-hoc test?
when the F-ratio is significant
