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[R-meta] metafor: standardized mean change using raw score standardization

Dear Wolfgang, 

Thank you very much for your clarification!
It was not so clear to me.

Best regards,
Spyros

-----Urspr?ngliche Nachricht-----
Von: Wolfgang Viechtbauer <wolfgang.viechtbauer at maastrichtuniversity.nl> 
Gesendet: Wednesday, August 7, 2019 2:05 PM
An: Spyridon Siafis <spyridon.siafis at tum.de>
Cc: r-sig-meta-analysis at r-project.org
Betreff: Re: [R-meta] metafor: standardized mean change using raw score standardization

Dear Spyros,

Indeed, 'sd2i' isn't needed, since escalc() computes yi=(m1i-m2i)/sd1i for measure="SMCR". If you have the mean change (and not the pre- and post-test means), then you can set m1i to the mean change and m2i to 0. 
But you will need to specify 'ri' and cannot simply assume it to be 0. The value of 'ri' won't change the size of 'yi', but it will influence the size of the sampling variance ('vi').

Best,
Wolfgang