R help - Sep 2008 - Ability estimates for partial credit model

Dear all,

I'm working on ability estimates using Rasch model. Using the
"ltm"
package, the procedure is quite simple:

## Factor Scores for the Rasch model
fit <- rasch(LSAT)
factor.scores(fit)

What about Partial Credit Model (PCM)? For PCM I use PCM function from 
eRm package. Is there any similar function like factor.scores to 
estimate ability scores using PCM model?

Best, Andrej

Dear all,

I'm working on ability estimates using Rasch model. Using the
"ltm"
package, the procedure is quite simple:

## Factor Scores for the Rasch model
fit <- rasch(LSAT)
factor.scores(fit)

What about Partial Credit Model (PCM)? For PCM I use PCM function from 
eRm package. Is there any similar function like factor.scores to 
estimate ability scores using PCM model?

Best, Andrej

Yes, see the irt.ability function in the MiscPsycho package. This has
methods for maximum likelihood, and the two common bayesian estimates
(MAP, EAP). I am right now writing code for test characteristic methods.

> -----Original Message-----
> From: r-help-bounces at r-project.org 
> [mailto:r-help-bounces at r-project.org] On Behalf Of Andrej Kastrin
> Sent: Thursday, September 18, 2008 8:15 AM
> To: r-help
> Subject: [R] Ability estimates for partial credit model
> 
> Dear all,
> 
> I'm working on ability estimates using Rasch model. Using the
"ltm"
> package, the procedure is quite simple:
> 
> ## Factor Scores for the Rasch model
> fit <- rasch(LSAT)
> factor.scores(fit)
> 
> What about Partial Credit Model (PCM)? For PCM I use PCM 
> function from eRm package. Is there any similar function like 
> factor.scores to estimate ability scores using PCM model?
> 
> Best, Andrej
> 
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide 
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>