[R-meta] P-values one or two-sided

Tina Dudenhöffer t|n@@dudenhoe||er @end|ng |rom gm@||@com
Mon Jun 28 15:43:28 CEST 2021

Thank you, all clear.

And yes, I was referring to the QM-test.

Thanks for the quick response,

> On 28 Jun 2021, at 15:40, Viechtbauer, Wolfgang (SP) <wolfgang.viechtbauer using maastrichtuniversity.nl> wrote:
> Dear Tina,
> Please see my responses below.
> Best,
> Wolfgang
>> -----Original Message-----
>> From: R-sig-meta-analysis [mailto:r-sig-meta-analysis-bounces using r-project.org] On
>> Behalf Of Tina Dudenhöffer
>> Sent: Monday, 28 June, 2021 15:32
>> To: r-sig-meta-analysis using r-project.org
>> Subject: [R-meta] P-values one or two-sided
>> Dear all,
>> I am working with the Metafor package using the rma.mv function.
>> I read that, by default, the p-values are reported for two-sided tests, so I am
>> wondering whether I should divide my p-values by two.
>> I am asking about the test of moderators specifically (when performing the Q-test
>> of Moderation).
> The p-value given there is a one-sided p-value (since this is for a chi-square / F-test). There is no need to adjust this p-value.
>> Similarly, when removing the intercept (i.e putting a -1 behind the moderator) I
>> assume that p-value is not two-sided?
> You mean for the QM-test? That's always reported as a one-sided p-value.
>> I am just not sure how much of the output is depending on R default and how much
>> is part of the Metafor package and how exactly it is set up.
>> Thanks for clarifying.
>> Kind regards,
>> Tina

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