sphericity

  1. S

    P value after Geisser-Greenhouse correction

    I have noticed that when Graphpad Prism does a sphericity correction using the Geisser-Greenhouse correction, it halves the P value for this source of variation (typically Treatments). For example, in the example I am working on, it calculates an F value of 20.25, with DF(num) = 1.391, and...
  2. A

    Could someone explain "sphericity in ANOVA" for me, please?

    Hi! Could someone explain "sphericity in ANOVA" for me, please? I am a complete dummy, so I need a "for dummies-explanation". I would be very grateful for the help. All the best!
  3. P

    Geisser-Greenhouse Correction Nonsignificant Effect

    I've read several pieces of documentation that say that the Geisser-Greenhouse correction for sphericity always increases the p value. I've noticed in SPSS that if a test is not significant (before any correction), sometimes the Geisser-Greenhouse corrected value is actually less than the...
  4. S

    Sample difference in repeated designs with control

    Hi everyone, as my computer crashed a few days ago, I lost the source to an article I was reading referring to how large the sample size deviation in repeated measures can be between treatment and control group. If I remember correctly it cited Stevens (might have been Student though) on how...
  5. R

    Differing p values on rep-measures ANOVA: Sphericity Assumed vs Multivar test

    I've run a 2x3x2 repeated measures ANOVA on SPSS. This brings an output with two tables that show you p values for the main effects and interactions. The first is called 'Multivariate Tests'. This gives 4 p-values for each contrast, however as I only run univariate analyses these 4 values...