[R-meta] pooled vs separate QB statistics

Hi Filippo,

That is correct.

Best,
Wolfgang

-----Original Message-----
From: R-sig-meta-analysis <r-sig-meta-analysis-bounces at r-project.org>

On Behalf

Of Filippo Gambarota via R-sig-meta-analysis
Sent: Tuesday, May 28, 2024 12:39
To: Michael Dewey <lists at dewey.myzen.co.uk>
Cc: Filippo Gambarota <filippo.gambarota at gmail.com>; R Special Interest

Group

for Meta-Analysis <r-sig-meta-analysis at r-project.org>
Subject: Re: [R-meta] pooled vs separate QB statistics

Dear Michael,
Thank you. So basically when different tau2 are estimated (either
using a multivariate model or scale location model) the Q test for the
moderators is the non-pooled test? When a single tau2 is estimated the
Q test is the pooled version?
Filippo

On Tue, 28 May 2024 at 12:31, Michael Dewey <lists at dewey.myzen.co.uk>

wrote:

Dear Filippo

Does

https://www.metafor-project.org/doku.php/tips:different_tau2_across_subgroups

help?

Michael

On 28/05/2024 11:09, Filippo Gambarota via R-sig-meta-analysis wrote:

Hi,
I was reading the two papers (at the end) about categorical

moderators

and the omnibus test and despite the conclusion is that the Q (or F)
test based on the pooled tau2 estimation works better in most cases,
when k in each moderator level is large and tau2 is expected to

differ

across levels, it is better to use the non-pooled method.

Reading the metafor documentation it is not clear to me how to
implement the non-pooled method. Maybe I am missing something but I
can change the type of test (z vs t vs knha that takes into account
tau2 uncertainty) but I see no option to choose the pooled vs non
pooled tau2 method.

Thanks
Filippo

Rubio-Aparicio, M., L?pez-L?pez, J. A., Viechtbauer, W.,
Mar?n-Mart?nez, F., Botella, J., & S?nchez-Meca, J. (2020). Testing
Categorical Moderators in Mixed-Effects Meta-analysis in the Presence
of Heteroscedasticity. Journal of Experimental Education, 88(2),
288?310. https://doi.org/10.1080/00220973.2018.1561404

Rubio-Aparicio, M., S?nchez-Meca, J., L?pez-L?pez, J. A., Botella,

J.,

& Mar?n-Mart?nez, F. (2017). Analysis of categorical moderators in
mixed-effects meta-analysis: Consequences of using pooled versus
separate estimates of the residual between-studies variances. The
British Journal of Mathematical and Statistical Psychology, 70(3),
439?456. https://doi.org/10.1111/bmsp.12092