[R-meta] Quick question about multiple independent samples within one study

[Anna-Lena Schubert]

Thanks for your helpful responses! I will quickly add a follow-up
question regarding implementation: Previously (before accounting for
dependencies within studies), my code looked like this:

        res <- rma.mv(yi, dat$V, mods = ~ var1var2 - 1, random = ~
var1var2 | id, struct="UN", data=dat$dat)

Here, I investigate whether the correlation with a criterion variable
differs between two predictors. Now, I have some studies with
independent samples (different age groups), while I have other studies
with different criterion variables within the same sample (different
measures). If I wanted to introduce both dependencies, I believe I could
change the code as follows:

        res <- rma.mv(yi, dat$V, mods = ~ var1var2 - 1, random = list(~
var1var2 | id, ~sample | id, ~measure | id), data=dat$dat)

Three concerns: First, is "sample | id" or "id | sample" appropriate?
Second, metafor tells me I can only have to random factors ("Only up to
two '~ inner | outer' formulas allowed in the 'random' argument"). Which
should I drop or is there a workaround? Third, I'm somewhat worrying I
might be overfitting. Is this a legit worry?

Best, Anna-Lena

Am 13.12.2018 um 16:01 schrieb Guido Schwarzer:
> Hi,
>
> I got this wrong (and gave a nice answer for a different question).
>
> See Wolfgang's email for the correct answer.
>
> Best wishes, Guido
>
-- 
Signatur


      Dr. Anna-Lena Schubert

Postdoc at Section of Personality
Heidelberg University - Institute of Psychology

Hauptstraße 47-51
D-69117 Heidelberg Germany

Phone: +49 6221 54 7746
Mail: anna-lena.schubert using psychologie.uni-heidelberg.de
Web: http://www.psychologie.uni-heidelberg.de/ae/diff/diff/people-schubert.html


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