Mauchly's sphericity test
Mauchly's sphericity test is used to test the assumption of sphericity in within-subject ANOVAs. This assumption is that: the difference scores between each within-subject variable have similar variances.
If Mauchly's sphericity test is significant (p < .05), then sphericity should not be assumed and adjustments to the degrees of freedom should be made using an adjustment such as:
- Greenhouse-Geisser
- Huyn-Feldt
- Lower-bound
Greenhouse-Geisser is commonly used and recommended.
See also
[edit | edit source]- Mauchly's sphericity test (Wikipedia)