[R] package metafor: specify weights?

[Anke Stein]

Dear R-experts,
Dear Wolfgang,

Weighted model fitting in metafor uses the inverse of the study specific variances as weights.
I am wondering if it is possible to specify different weights.

In my meta-analysis, there are two types of studies with (intrinsic) differences in their range of sample sizes (which are used to calculate the variances of Fisher's z).
I would like to try normalizing the sample sizes within each set of the two study types and use these normalized sample sizes as weights.
Would that be possible with rma()? So far, I only found the option "weighted = TRUE/FALSE", but no possibility to specify which weights should be used.

Many thanks in advance,
Anke






-- 
__________________________________________________________
Anke Stein (Dipl.-Biol.)

Biodiversity, Macroecology & Conservation Biogeography
Head Prof. Dr. Holger Kreft
Georg-August University of Göttingen
Büsgenweg 2 | 37077 Göttingen | Germany

phone +49(0)551-39-13761
fax +49(0)551-39-3618
astein at uni-goettingen.de
http://www.uni-goettingen.de/biodiversity