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:

  1. Greenhouse-Geisser
  2. Huyn-Feldt
  3. Lower-bound

Greenhouse-Geisser is commonly used and recommended.

See also

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