jamovi

I have been using Jamovi version 1.6.23 for meta-analysis, with a random-effects model fitted to the data, and using the standardized mean difference (SMD) as the outcome measure. Does anyone know if the SMD that Jamovi provides is exactly Cohen’s d? or is the SMD given by Jamovi calculated with a different formula (different from Cohen's d)?

is this for the MAJOR module? it's helpful if you mention the module you're using.

i'm not actually sure what the SMD is.

cheers

jonathon

Yes, this would be for the MAJOR module. I don't know what estimator is used for the calculation of the standardized mean difference (SMD) in this module. SMDs are usually estimated by Cohen's d or Hedges' g. I was wondering if someone knew how SMDs are estimated in the MAJOR module of Jamovi.

Cheers,

Francisco

frbp wrote: Does anyone know if the SMD that Jamovi provides is exactly Cohen’s d? or is the SMD given by Jamovi calculated with a different formula (different from Cohen's d)?

Hey Francisco,
Standardized Mean Difference (SMD) was one of the first effect dimensions used in published meta-analyzes (Larry V. Hedges & Olkin 1985) and remains widely used.
There are many ways to calculate the SMD for a data set.
In jamovi the MAJOR module imports/uses Wolfgang Viechtbau's metafor R package.

It's called Hedge's g (Hedges, 1981), in the metafor package, the default value for SMD.

Cheers, Maurizio

Hi Maurizio,

Thank you very much for the clarification.

Cheers,

Francisco