All Questions
7 questions
29
votes
3
answers
47k
views
Differences between MANOVA and Repeated Measures ANOVA?
What is the difference between a repeated measures ANOVA over some factor (say experimental condition) and a MANOVA?
In particular one website I stumbled across suggested that MANOVA does not make the ...
- 19k
2
votes
2
answers
706
views
Does sphericity (an RM-ANOVA assumption) require the covariances between difference scores to be the same?
Field's Discovering Statistics Using SPSS (2013, Sage) defines sphericity as follows:
Sphericity: a less restrictive form of compound symmetry which assumes
that the variances of the differences ...
11
votes
3
answers
3k
views
Why does repeated measures ANOVA assume sphericity?
Why does repeated measures ANOVA assume sphericity?
By sphericity I mean the assumption that the variance of all pairwise differences between groups should be the same.
In particular, I don't ...
5
votes
2
answers
11k
views
Bonferroni and Greenhouse-Geisser corrections with repeated-measures ANOVA
I guess my question comes in two parts:
Following a 1x7 repeated-measures ANOVA, I carried out 3 pre-planned tests. Two were t-tests between 2 of the conditions. The third is a 1x6 ANOVA (to test ...
- 71
4
votes
1
answer
650
views
Why is compound symmetry sufficient to establish sphericity?
At this website it is stated that "If compound symmetry is met then sphericity is also met."
Is it impossible to construct a data set that has perfect compound symmetry but not perfect sphericity? ...
4
votes
1
answer
352
views
Why is the "sphericity assumption" in RM-ANOVA (constant variance of difference scores) called "sphericity"?
Why is the "sphericity assumption" in RM-ANOVA, i.e. the assumption of constant variance of difference scores, called "sphericity"?
(This question was suggested in the comments to a related question.)...
-1
votes
1
answer
49
views
Accuracy vs Precision: Can I use the Sphercity Assumption data in a meaningful way?
I understand that when conducting a repeated measures design with say one factor having three levels (Training: None, Standard, New Method), in the analysis you want the sphercity assumption to not be ...
- 25