[R] Inserting weights in ltm package

[Erica Crome]

Afternoon R help,

I want to run Rasch/IRT analyses using the ltm package, however, I am
using large scale survey data which requires weighting for accurate
results. I attempted to create a weighted object to insert into the
formulae of the ltm packages, however, the survey data only includes
30 replicate weights and a sampling weight. The svrepdesign requires
additional information  such as jacknife weights in an external object
(for scale, rscale), however, I do not have these. I typically just
use the sampling weight when doing analyses in other platforms such as
MPlus, however there does not appear to a way of referring to this
directly in the ltm formulae.

My question is: am I able to insert sampling weights directly into an
ltm analysis, or is there a way of creating a weighted data object
with the information available which I could then insert into the ltm
analyses? I have been unable to find any similar help topics using the
websearch. Thanks.

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