mokken (version 2.7.2)

check.pmatrix: Check of Nonintersection Using Method Pmatrix

Description

Returns a list (of class pmatrix.class) with results from the investigation of nonintersection using method pmatrix (Mokken, 1971; Molenaar and Sijtsma, 2000; Sijtsma and Molenaar, 2002).

Usage

check.pmatrix(X, minvi = 0.03)

Arguments

X

matrix or data frame of numeric data containing the responses of nrow(X) respondents to ncol(X) items. Missing values are not allowed

minvi

minimum size of a violation that is reported

Value

• results
  A list with as many components as there are item pairs. Each component itself is also a list containing the results of the check of nonintersection using Method pmatrix. The P(++) matrix and P(- -) (Molenaar and Sijtsma, 2000; Sijtsma and Molenaar, 2002) are also included.
• I.item
  vector indicating to which items the rows and column the P(++) matrix belong
• I.step
  the labels of the item steps in order of popularity
• I.labels
  the item labels
• Hi
  the item scalability coefficients Hi
• minvi
  the value of minvi

Details

The output is often numerous. Functions plot and summary can be used to summarize the output. See Van der Ark (2007) for an example.

References

Mokken, R. J. (1971) A Theory and Procedure of Scale Analysis. Berlin, Germany: De Gruyter. 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/v20/i11

See Also

check.errors, check.iio, check.monotonicity, check.reliability check.restscore, coefH, plot.pmatrix.class, summary.pmatrix.class

Examples

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