# Evaluation of Model-Data Fit in Item Response Theory (IRT) and Useful Functions Related to IRT

## Documentation for package ‘irtplay’ version 1.2.0

- DESCRIPTION file.

## Help Pages

irtplay-package | irtplay: Evaluation of model-data fit in Item Response Theory (IRT) and useful functions related to IRT
bind.fill | Bind Fill
bring.bilog | Import Item and Ability Parameters from IRT Software
bring.flexmirt | Import Item and Ability Parameters from IRT Software
bring.mirt | Import Item and Ability Parameters from IRT Software
bring.parscale | Import Item and Ability Parameters from IRT Software
covirt | Asymptotic variance-covariance matrices of item parameter estimates
drm | Dichotomous Response Model Probabilities
est_item | Fixed effect item parameter calibration
est_score | Estimate examinees' ability (proficiency) parameters
gen.weight | Generate Weights
irtfit | Traditional IRT item fit statistics
irtfit.default | Traditional IRT item fit statistics
irtfit.est_item | Traditional IRT item fit statistics
llike_item | Loglikelihood of Items
lwrc | Lord-Wingersky Recursion Formula
plm | Polytomous Response Model Probabilities (GRM and GPCM)
plot.irtfit | Draw raw and standardized residual plots
plot.test.info | Plot Item and Test Information Functions
plot.traceline | Plot ICC and TCC
shape_df | Create a data.frame of Item Meta Data
simCAT_DC | Simulated single-item format CAT Data
simCAT_MX | Simulated mixed-item format CAT Data
simdat | Simulated Response Data
sx2_fit | S-X2 fit statistic
sx2_fit.default | S-X2 fit statistic
sx2_fit.est_item | S-X2 fit statistic
test.info | Item and Test Information Function
test.info.default | Item and Test Information Function
test.info.est_item | Item and Test Information Function
traceline | Compute Item/Test Characteristic Functions
traceline.default | Compute Item/Test Characteristic Functions
traceline.est_item | Compute Item/Test Characteristic Functions
write.flexmirt | Write a "-prm.txt" file for flexMIRT