mokken (version 1.2)

plot.monotonicity.class: Plot monotonicity.class objects

Description

S3 Method to plot objects of class monotonicity.class. Graphic display of the checks of monotonicity. One graph for each item plotting the estimated item step response functions.

Usage

## S3 method for class 'monotonicity.class':
plot(x, items = all, ...)

Arguments

x

Object of class monotonicity.class produced by check.monotonicity.

items

vector containing the numbers of the items for which the results are depicted graphically. Default the results for all items are depicted.

...

Optional graphical parameters will be ignored

Value

• Returns a graph.

Details

The default graphic device in R may only display the last graph.

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.monotonicity, summary.monotonicity.class

Examples

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