Dear all,
I am working with the rma.uni function to fit a multivariate random effects model.
I see that the W argument is an optional argument to specify a user-defined weight matrix. I was curious if any weight is applied if I don?t specify this argument.
Specifically, I am wondering if the inverse variance weight is applied ?automatically?, considering I am specifying the V argument in the model itself.
In terms of my model, I am wondering about the difference between these:
res5 <- rma.mv(EffectSize_NEW, Variance_New, method="REML",random = list(~ 1 | EffectSize_ID_NEW, ~ 1 | Study), data=Data)
res5
res6 <- rma.mv(EffectSize_NEW, Variance_New, W=weight, method="REML",random = list(~ 1 | EffectSize_ID_NEW, ~ 1 | Study), data=Data)
res6
Note: the argument weight in my dataset is simply: 1/Variance_New
Hope this is all clear.
Many thanks and kind regards,
Tina