jamovi

With my samples (48 observations) the two methods differ a lot in their results :
d = 0.41 with Jamovi using d=(m1-m2)/SDdif
d = 0.27 (Python pingouin) using d=(m1-m2)/pooledSD
This is because the standard deviation of the differences is not the same as the pooled standard deviation of the two ...

Hi Magojam
Thank you for your answer
In https://github.com/jamovi/jmv/blob/master/R/ttestps.b.R#L66-L68
I see that
d <- (m1-m2)/pooledSD #Cohen's d
with
pooledSD <- tryNaN(stats::sd(column1-column2))
but this is not the pooled SD, it the SD of the difference.

Python pingouin.ttest uses for the ...

Hello. The Cohen's d effect size given by Jamovi (version 2.2.5.0) for T test for two paired samples is not the same as the one I calculate by hand (means dif/pooled_sd) or the one given by Python pingouin.ttest module.
For T test for independent samples, the Conhen’s d given by Jamovi is the same ...