Two-Way ANOVA 2 (1) Flashcards
What is the assumption of a repeated-measures two-way ANOVA?
The assumption of sphericity (similar to the assumption of homogeneity for between-subject variance- however, with sphericity, the differences between each pair of scores should have equal variances).
In which circumstance is the assumption of sphericity not met?
If Mauchly’s Test is significant, signifying that there are significant differences between the variances of differences.
For what does the homogeneity of variance test?
Whether the variance of each group being investigated is similar.
How can we test for homogeneity of variance?
With Levene’s Test.
In which circumstance is the homogeneity of variance significant?
If the variance of each group being investigated is not the same.
For what does sphericity test?
Whether the variance of the differences between each group being investigated is similar.
How can we correct for violations of sphericity?
By reducing our degrees of freedom, and therefore making our ANOVA test more conservative.
What increases the likelihood of obtaining a significant result from an ANOVA test?
A larger degrees of freedom (relative to sample size).
Under which circumstance is there only one covariate?
When there are only two levels of a factor.
Under which circumstance is the assumption of sphericity automatically met?
When there is only one covariate.
In which case will SPSS print a value of 1.00 for the Mauchly statistic and no value for its significance?
In the case of the assumption of sphericity being automatically met due to there being only one covariate.
What are the three types of violation of sphericity correction?
- Greenhouse Geisser
- Huynh Feldt
- Lower Bound
To which value is it appropriate to refer if Mauchly’s test is not significant?
To the ‘Sphericity Assumed’ value.
Which violation of sphericity correction is it recommended to use if its epsilon is less than 0.75?
The Greenhouse Geisser correction.
Which violation of sphericity correction is it recommended to use if the Greenhouse Geisser epsilon is above 0.75?
The Huynh Feldt correction.
