similar to: New package: equate

Dear R-users, I'd like to announce the release of the new version of package `ltm' (i.e., ltm_0.8-0 soon available from CRAN) for Item Response Theory analyses. This package provides a flexible framework for analyzing dichotomous and polytomous data under IRT, including the Rasch model, the Two-Parameter Logistic model, Birnbaum's Three-Parameter model, the Latent Trait model

Dear R-users, I'd like to announce the release of the new version of package `ltm' (i.e., ltm_0.8-0 soon available from CRAN) for Item Response Theory analyses. This package provides a flexible framework for analyzing dichotomous and polytomous data under IRT, including the Rasch model, the Two-Parameter Logistic model, Birnbaum's Three-Parameter model, the Latent Trait model

Hi Xavier, the reason you observe this feature is that in the 'constraint' argument you should specify the values under the additive parameterization, i.e., when in the second column of the matrix supplied in 'constraint' you specify 2, then you need to provide the easiness parameters (not the difficulty parameters) in the third column. Check the Details section of ?tpm() and

Dear R-users, I'd like to announce the release of the new version of package 'ltm' (i.e., ltm_0.9-0 soon available from CRAN) for Item Response Theory analyses. This package provides a flexible framework for analyzing dichotomous and polytomous data under various IRT models. Furthermore, supporting functions for descriptive statistics, goodness-of-fit, ability estimation and

Dear R-users, I'd like to announce the release of the new version of package 'ltm' (i.e., ltm_0.9-0 soon available from CRAN) for Item Response Theory analyses. This package provides a flexible framework for analyzing dichotomous and polytomous data under various IRT models. Furthermore, supporting functions for descriptive statistics, goodness-of-fit, ability estimation and

Dear list, There is a new rwiki (http://rwiki.sciviews.org) section for 'large scale data' at http://rwiki.sciviews.org/doku.php?id=large_scale_data. This is a massive topic of interest to many. I could use some help filling in the content so that this can develop into a powerful resource for the r-community. I hope you like it, and I hope you are willing to help make it better.

Dear all, I am trying to optimize a logistic function using optim, inside the following functions: #Estimating a and b from thetas and outcomes by ML IRT.estimate.abFromThetaX <- function(t, X, inits, lw=c(-Inf,-Inf), up=rep(Inf,2)){ optRes <- optim(inits, method="L-BFGS-B", fn=IRT.llZetaLambdaCorrNan, gr=IRT.gradZL, lower=lw, upper=up, t=t, X=X)

I was told to go to packages on the tool bar and select 'install packages'. Then choose library (equate). My R is version 2.11. I tried multiple times with different locations of R within US. Yet, I didn't see library(equate) being offered in the packages. Thanks. Grace [[alternative HTML version deleted]]

I need a picture like this: http://rwiki.sciviews.org/doku.php?id=graph_gallery:graph38 http://rwiki.sciviews.org/doku.php?id=graph_gallery:graph38 but when I try compile it require("hexbin") data(NHANES)# pretty large data set! good <- !(is.na(NHANES$Albumin) | is.na(NHANES$Transferin)) NH.vars <- NHANES[good,

The first version of the package plink has been uploaded to CRAN. plink is a package for conducting unidimensional IRT scaling and chain linking for multiple groups for single-format or mixed-format common items. The package supports eight IRT models and four calibration methods. Dichotomous Models: 1PL, 2PL, 3PL Polytomous Models: -Graded response model -Partial credit model -Generalized

The first version of the package plink has been uploaded to CRAN. plink is a package for conducting unidimensional IRT scaling and chain linking for multiple groups for single-format or mixed-format common items. The package supports eight IRT models and four calibration methods. Dichotomous Models: 1PL, 2PL, 3PL Polytomous Models: -Graded response model -Partial credit model -Generalized

---------- Forwarded message ---------- From: <r-help-bounces@r-project.org> Date: Mon, May 11, 2009 at 10:24 PM Subject: The results of your email commands To: das.moumita.online@gmail.com The results of your email command are provided below. Attached is your original message. - Results: Ignoring non-text/plain MIME parts - Unprocessed: What is the function for partial

In the near future I will release MiscPsycho, a package that contains various functions useful for applied psychometricians. I would like to include some data sets for distribution in the package, but have not created any of these on my own, but have used data distributed in other packages such as the LSAT data in the ltm package. Is it appropriate for me to distribute a data set in the package I

Per http://rwiki.sciviews.org/doku.php?id=developers:projects:gsoc2010 -- and http://rwiki.sciviews.org/doku.php?id=developers:projects:gsoc2010:syrfr -- I am applying to mentor the "Symbolic Regression for R" (syrfr) package for the Google Summer of Code 2010. I propose the following test which an applicant would have to pass in order to qualify for the topic: 1. Describe each of the

Does anyone know how to get cumulative frequency percentage and how to access library (equate)? Thanks. Grace [[alternative HTML version deleted]]

An updated version of the package plink has been uploaded to CRAN. This is a major revision that now includes multidimensional models and methods. plink is a package for conducting unidimensional and multidimensional IRT-based test linking using separate calibration methods for multiple groups for single-format or mixed-format common items. The package supports sixteen IRT models and eleven

An updated version of the package plink has been uploaded to CRAN. This is a major revision that now includes multidimensional models and methods. plink is a package for conducting unidimensional and multidimensional IRT-based test linking using separate calibration methods for multiple groups for single-format or mixed-format common items. The package supports sixteen IRT models and eleven

Hola, A lo mejor la solución pasa por ver si Statgraphics puede exportar su fichero a otro formato de cualquiera de los que R sí que puede leer. No sé si además del fichero, tienes acceso a Statgraphics.... Saludos, Carlos Ortega www.qualityexcellence.es El 12 de junio de 2013 13:26, Roberto <rv.tec@zoho.com> escribió: > Hola, es la primera lista en la que participo, espero no meter

Hi my friends, I'm very new to R and need your help. I used R and ltm package for item response theory (IRT) modeling. I also need to compute differential item function (DIF) for IRT models. I searched the archive but basically found nothing. Could you help me find some sources about handling DIF of IRT? Many thanks in advance! Feng

For info, I put a little study I did about the byte code compiler and other speedup approaches (but not multicore) on the Rwiki at http://rwiki.sciviews.org/doku.php?id=tips:rqcasestudy which looks at a specific problem, so may not be relevant to everyone. However, one of my reasons for doing it was to document the "how to" a little. JN > > 2. Have you tried the