[R-meta] pooled vs separate QB statistics

[Filippo Gambarota]

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 using 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., López-López, J. A., Viechtbauer, W.,
> > Marín-Martínez, F., Botella, J., & Sánchez-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., Sánchez-Meca, J., López-López, J. A., Botella, J.,
> > & Marín-Martínez, 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
> >
>
> --
> Michael



-- 
Filippo Gambarota, PhD
Postdoctoral Researcher - University of Padova
Department of Developmental and Social Psychology
Website: filippogambarota.xyz
Research Groups: Colab   Psicostat