mokken (version 1.2)

plot.restscore.class: Plot restscore.class objects

Description

S3 Method to plot objects of class restscore.class. Graphic display of the checks of restscore. One graph for each item pair plotting the estimated item step response functions. Intersection of the lines indicates vaiolation of nonintersection,

Usage

## S3 method for class 'restscore.class':
plot(x, item.pairs = all, ...)

Arguments

x

Object of class restscore.class produced by check.restscore.

item.pairs

vector containing the numbers of the item pairs for which the results are depicted graphically. For example, item.pairs = 1 prints the results for items 1 and 2, item.pairs = 2 prints the results for items 1 and 3,

...

Optional graphical parameters will be ignored

Value

• Returns a graph.

Details

The default graphic device in R may only display the last graph. The default number of plots can increase rapidly for large numbers of items.

References

Molenaar, I.W. and Sijtsma, K. (2000) User's Manual MSP5 for Windows [Software manual]. Groningen, The Netherlands: IEC ProGAMMA. Sijtsma, K, and Molenaar, I. W. (2002) Introduction to nonparametric item response theory. Thousand Oaks, CA: Sage. Van der Ark, L. A. (2007). Mokken scale analysis in R. Journal of Statistical Software. http://www.jstatsoft.org

See Also

check.restscore, summary.restscore.class

Examples

data(acl)
restscore.list <- check.restscore(acl[,1:10])
plot(restscore.list)
summary(restscore.list)