[R-meta] meta-regression: categorical

[P. Roberto Bakker]

Hi everybody,

In:
http://www.metafor-project.org/doku.php/analyses:vanhouwelingen2002
'allocation' is put in syntax without dummy coding

rma <http://finzi.psych.upenn.edu/library/metafor/html/rma.uni.html>(yi,
vi, mods = ~ alloc, data
<http://stat.ethz.ch/R-manual/R-devel/library/utils/html/data.html>=dat,
method="ML")

If I am not wrong, 'allocation' is a catergorical variabel, and I suppose
the R handles the coding of dummy automatically.
Correct?

I found this information in:
https://cran.r-project.org/web/packages/metafor/metafor.pdf
*Categorical moderator variables can be included in the model via the mods
argument in the same way that appropriately (dummy) coded categorical
independent variables can be included in linear models. One can either do
the dummy coding manually or use a model formula together with the factor
function to let R handle the coding automatically.   *

*Best wishes and thank you in advance*
*Roberto*

	[[alternative HTML version deleted]]