[R-meta] effect size similarities

[Viechtbauer, Wolfgang (SP)]

That is just a simple z-test of a single binomial proportion. This cannot be turned into a standardized mean difference (Cohen's d / Hedges' g value) or vice-versa.

Best,
Wolfgang

>-----Original Message-----
>From: Patrizio E Tressoldi [mailto:patrizio.tressoldi using unipd.it]
>Sent: Tuesday, 22 June, 2021 16:01
>To: Viechtbauer, Wolfgang (SP); r-sig-meta-analysis using r-project.org
>Subject: Re: [R-meta] effect size similarities
>
>Il 22/06/2021 15:54, Viechtbauer, Wolfgang (SP) ha scritto:
>> Dear Patrizio,
>>
>> I don't know what exactly you mean by 'binomial z value', but Hedges' g is not a
>'z score'. If that were the case, then g values would have a variance of 1, which
>is clearly not true.
>>
>Here you can see the formula:
>
>https://www.mathcelebrity.com/binomial.php?n=10&p=0.4&k=3&t=&pl=Normal+Approximati
>on
><https://www.mathcelebrity.com/binomial.php?n=10&p=0.4&k=3&t=&pl=Normal+Approximat
>ion>
>
>Given you said they are different, how they must be transformed for
>their comparison?
>
>Thanks
>
>Patrizio