runolr: runs ordinal logistic regression models

In lordif: Logistic Ordinal Regression Differential Item Functioning using IRT

Description

Runs ordinal logistic regression models and produces DIF statistics and effect size measures

Usage

runolr(rv, ev, gr, wt)

Arguments

rv	a response variable
ev	an explanatory variable (e.g., conditioning variable)
gr	a vector of group identifiers
wt	a vector of optional sample weights

Details

Model 1: ev

Model 2: ev + gr

Model 3: ev*gr or equivalently ev + gr + ev*gr

Value

Returns a list of the following components:

chi12	prob for the LR Chi-square comparing Model 1 vs. Model 2
chi13	prob for the LR Chi-square comparing Model 1 vs. Model 3
chi23	prob for the LR Chi-square comparing Model 2 vs. Model 3
beta12	proportional change in the coefficient for ev
pseudo1.CoxSnell	Cox & Snell psudo R-square for Model 1
pseudo2.CoxSnell	Cox & Snell psudo R-square for Model 2
pseudo3.CoxSnell	Cox & Snell psudo R-square for Model 1
pseudo1.Nagelkerke	Nagelkerke psudo R-square for Model 1
pseudo2.Nagelkerke	Nagelkerke psudo R-square for Model 2
pseudo3.Nagelkerke	Nagelkerke psudo R-square for Model 3
pseudo1.McFadden	McFadden psudo R-square for Model 1
pseudo2.McFadden	McFadden psudo R-square for Model 2
pseudo3.McFadden	McFadden psudo R-square for Model 3
pseudo12.CoxSnell	Cox & Snell R-square change from Model 1 to Model 2
pseudo13.CoxSnell	Cox & Snell R-square change from Model 1 to Model 3
pseudo23.CoxSnell	Cox & Snell R-square change from Model 2 to Model 3
pseudo12.Nagelkerke	Nagelkerke R-square change from Model 1 to Model 2
pseudo13.Nagelkerke	Nagelkerke R-square change from Model 1 to Model 3
pseudo23.Nagelkerke	Nagelkerke R-square change from Model 2 to Model 3
pseudo12.McFadden	McFadden R-square change from Model 1 to Model 2
pseudo13.McFadden	McFadden R-square change from Model 1 to Model 3
pseudo23.McFadden	McFadden R-square change from Model 2 to Model 3
df12	df for the LR Chi-square comparing Model 1 and Model 2
df13	df for the LR Chi-square comparing Model 1 and Model 3
df23	df for the LR Chi-square comparing Model 2 and Model 3

Author(s)

Seung W. Choi <[e-mail]>

References

Choi, S. W., Gibbons, L. E., Crane, P. K. (2011). lordif: An R Package for Detecting Differential Item Functioning Using Iterative Hybrid Ordinal Logistic Regression/Item Response Theory and Monte Carlo Simulations. Journal of Statistical Software, 39(8), 1-30. URL http://www.jstatsoft.org/v39/i08/.

Crane, P. K., Gibbons, L. E., Jolley, L., & van Belle, G. (2006). Differential item functioning analysis with ordinal logistic regression techniques: DIF detect and difwithpar. Medical Care, 44(11 Suppl 3), S115-S123.

See Also

rundif, lordif, rms

Examples

## Not run: runolr(rv, ev, gr)

Example output

Loading required package: mirt
Loading required package: stats4
Loading required package: lattice
Loading required package: rms
Loading required package: Hmisc
Loading required package: survival
Loading required package: Formula
Loading required package: ggplot2

Attaching package: 'Hmisc'

The following objects are masked from 'package:base':

    format.pval, round.POSIXt, trunc.POSIXt, units

Loading required package: SparseM

Attaching package: 'SparseM'

The following object is masked from 'package:base':

    backsolve

lordif documentation built on May 2, 2019, 2:13 p.m.