Package: irtplay
Type: Package
Title: Online Item Calibration, Scoring, and Evaluation of Model-Data
        Fit in Item Response Theory
Version: 1.4.1
Description: Calibrate online item parameters (i.e., pretest and operational items), 
    estimate examinees abilities, and examine the IRT model-data fit on item-level 
    in different ways as well as provide useful functions related to unidimensional 
    item response theory (IRT) models. For the online calibration, Stocking's 
    Method A (Ban, Hanson, Wang, Yi, & Harris (2011) <doi:10.1111/j.1745-3984.2001.tb01123.x>) is 
    provided. More methods of online calibration (e.g., fixed item parameter calibration) 
    will be included in the future updated version. For the ability estimation, several 
    popular scoring methods (e.g., MLE, EAP, and MAP) are implemented. In terms of 
    assessing the IRT model-data fit, one of distinguished features of this package 
    is that it gives not only well-known item fit statistics (e.g., chi-square (X2), likelihood
    ratio chi-square (G2), infit and oufit statistics, and S-X2 statistic 
    (Ames & Penfield (2015) <doi:10.1111/emip.12067>)) but also graphical displays 
    to look at residuals between the observed data and model-based predictions 
    (Hambleton, Swaminathan, & Rogers (1991, ISBN:9780803936478)). 
    In addition, there are many useful functions such as computing asymptotic 
    variance-covariance matrices of item parameter estimates (Li & Lissitz (2004) 
    <doi:10.1111/j.1745-3984.2004.tb01109.x>), importing item and/or ability parameters 
    from popular IRT software, running 'flexMIRT' (Cai, 2017) through R, generating simulated 
    data, computing the conditional distribution of observed scores using the Lord-Wingersky 
    recursion formula (Lord & Wingersky (1984) <doi:10.1207/s15324818ame1002_1>), computing 
    the loglikelihood of individual items, computing the loglikelihood of 
    abilities, computing item and test information functions, computing item and 
    test characteristic curve functions, and plotting item and test 
    characteristic curves and item and test information functions.
Depends: R (>= 3.6)
License: GPL (>= 2)
Encoding: UTF-8
LazyData: true
Imports: stats, statmod, utils, reshape2, dplyr, tidyr, purrr, ggplot2,
        rlang, gridExtra, parallel, pbapply,
Authors@R: c(person("Hwanggyu", "Lim", email="hglim83@gmail.com", role=c("aut", "cre")),
    person("Craig S.", "Wells", email="cswells@educ.umass.edu ", rol="ctb")
    ) 
RoxygenNote: 6.1.1
Suggests: mirt
NeedsCompilation: no
Packaged: 2020-02-21 20:49:19 UTC; hlim
Author: Hwanggyu Lim [aut, cre],
  Craig S. Wells [ctb]
Maintainer: Hwanggyu Lim <hglim83@gmail.com>
Repository: CRAN
Date/Publication: 2020-02-21 23:10:02 UTC
Built: R 4.0.0; ; 2020-04-10 09:15:00 UTC; windows
