L11: REPEATED MEASURES ANOVA Flashcards
(19 cards)
What is a repeated measures ANOVA?
It’s the within-subjects version of a one-way ANOVA used to test differences between three or more conditions in the same group of participants.
What does repeated measures ANOVA test?
It tests the null hypothesis that the population means across all conditions are equal
What is an example of a repeated measures ANOVA design?
A study testing if cycling speed (slow, medium, high) affects reaction time to hazards, where each participant cycles at all three speeds in randomized order and reaction time is measured.
What is the independent variable and its levels in this example?
Cycling speed with 3 levels: low, medium, and high.
When should you use a repeated measures ANOVA?
When you have a within-subjects design where each participant takes part in all conditions, and you want to compare three or more levels of one factor.
What type of data is required for a repeated measures ANOVA?
Interval or ratio data (e.g., IQ scores, reaction times).
What kind of design involves each participant taking part in every condition?
A within-subjects or repeated measures design
When does data normally distributed show?
Like a dome with equal sides
What does positive skew show?
Goes towards the left side
What does the negative skew show?
Goes to the right
How to calculate the f value?
F = variance between conditions / variance within conditions
The less the variance there is within conditions the higher the f value will be
The more variance there is between conditions, the higher the F value will be - more likely to be significant
What is the main difference between repeated measures ANOVA and one-way ANOVA?
In repeated measures ANOVA, the same participants take part in all conditions, while in one-way ANOVA, different participants are in each group.
Why does repeated measures ANOVA reduce some variation within conditions?
Because the variation due to differences between people is controlled for, since the same people are measured in all conditions.
Why do we use post-hoc tests after a repeated measures ANOVA?
To test which specific conditions differ from each other
What is the problem with running multiple post-hoc t-tests?
It increases the chance of Type 1 errors (false positives).
How does the Bonferroni correction help with multiple post-hoc tests?
It makes the significance criteria more stringent to reduce Type 1 errors
What is a downside of applying the Bonferroni correction?
It increases the likelihood of Type 2 errors (false negatives).
Which of the following could be analysed using a repeated measures
ANOVA?
a. Comparing school readiness between children born before, during,
or after Covid lockdowns.
b. Examining your choice of drink (tea, coffee, or water) at three
different time points during the day.
c. Analysing whether you eat more chocolate before or after watching a
romantic movie
d. Using a longitudinal design to measure whether the same children’s
height differs between ages 8, 10, and 12
D
• How would you report the results
of this repeated measures ANOVA
to APA style?
a. F(24.133, 140.533) = 3.26, p =
.049, η2 = .147
b. F(2, 38) = 3.26, p = .049, η2 = .147
c. F(2, 19) = 3.91, p = .049, η2 = .147
d. F = 3.26, p = .049, η2 = .147
B
