Effect size measure from 3dLME

AFNI Message Board
1

Hello,

Is it possible to calculate an effect size akin to eta squared from the output of 3dLME?

Thank you,
Catherine

2

Catherine,

I’m not aware of an approach to computing eta-squared under the LME framework. On other other hand, would the effect magnitude itself (estimated by 3dLME) be much better than the dimensionless value of eta-squared? At least effect magnitude carries physical meaning and can be directly interpreted.

3

Thank you for the reply. To clarify, when you refer to effect magnitude, are you referring to the F value that is the default output?

4

I was referring to simple effects such as contrasts. F-statistic is omnibus and is usually for composite effects, which need to be further partitioned anyway.