lordif (version 0.4.2)

rundif: runs ordinal logistic regression DIF

Description

Runs ordinal logistic regression DIF

Usage

rundif(item, resp, theta, gr, criterion, alpha, beta.change, pseudo.R2, R2.change, wt)

Value

Returns a list of the following components:

stats

a data frame containing output statistics

flag

a logical vector of DIF flags

Arguments

item

a selection of items to be analyzed

resp

a data frame containing item responses

theta

a conditioning (matching) variable

gr

a vector of group identifiers

criterion

criterion for flagging (i.e., "CHISQR", "R2", or "BETA")

alpha

significance level for Chi-squared criterion

beta.change

proportional change for Beta criterion

pseudo.R2

pseudo R-squared measure (i.e., "McFadden", "Nagelkerke", or "CoxSnell")

R2.change

R-squared change for pseudo R-squared criterion

wt

optional sample weights

Author

Seung W. Choi <[e-mail]>

Details

The argument item lists the column numbers of the data frame resp to be included in the analysis.

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., and 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

runolr, lordif

Examples

if (FALSE) rundif(item,resp,theta,gr)