mokken (version 3.1.2)

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 & Sijtsma, 2000; Sijtsma & Molenaar, 2002).

Usage

check.pmatrix(X, minvi = 0.03)

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 & Sijtsma, 2000; Sijtsma & 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

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

Author

L. A. van der Ark

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. De Gruyter.

Molenaar, I.W., & Sijtsma, K. (2000) User's Manual MSP5 for Windows [Software manual]. IEC ProGAMMA.

Sijtsma, K., & Molenaar, I. W. (2002) Introduction to nonparametric item response theory. Sage.

Van der Ark, L. A. (2007). Mokken scale analysis in R. Journal of Statistical Software. tools:::Rd_expr_doi("10.18637/jss.v048.i05")

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)