summary of objects of class pmatrix.class.
Summarize checks of nonintersection using method pmatrix.## S3 method for class 'pmatrix.class':
summary(object, ...)check.pmatrixncol(X) rows and 10 columns,
showing for each item a summary of the violations of nonintersection using method pmatrix:
itemH = Item-scalability coefficient;
#ac} = number of active pairs that were investigated;
#vi} = number of violations in which the item is involved;
#vi/#ac} = propotion of active pairs that is involved in a violation;
maxvi = maximum violation;
sum = sum of all violations;
zmax = maximum z-value;
zsig = number of significant z-values;
crit = Crit value (Molenaar and Sijtsma, 2000, pp. 49, 74).
For obtaining the P++ and P-- matrix, see examples.
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
[object Object]
check.pmatrix, plot.pmatrix.classdata(acl)
Communality <- acl[,1:10]
pmatrix.list <- check.pmatrix(Communality)
plot(pmatrix.list)
summary(pmatrix.list)
# Small example showing how to retrieve the P++ matrix and the P-- matrix
SmallExample <- acl[,1:4]
pmatrix.list <- check.pmatrix(SmallExample)
pmatrix.list$results$Ppp
pmatrix.list$results$Pmm
summary
pmatrix