search.normal {mokken} | R Documentation |
Returns a vector with as many elements as there are items, indicating the scale an item belongs to
search.normal(X, lowerbound = 0.3, alpha = 0.05)
X |
matrix or data frame of numeric data
containing the responses of nrow(X) respondents to ncol(X) items.
Missing values are not allowed |
lowerbound |
numeric scaling criterium; 0 <= lowerbound < 1 |
alpha |
Type I error level |
The number of Mokken scales cannot exceed ncol(X)/2
.
Procedure may be slow for large data sets.
An indicator vector of length J. Each entry refers to an item. Items with same integer belong to the same Mokken scale. A zero indicates an unscalable item. If n is the largest integer, then n Mokken scales were found.
L. A. van der Ark a.vdark@uvt.nl
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
coefH
, check.iio
, check.monotonicity
, check.pmatrix
, check.reliability
,check.restscore
data(acl) # Partition all 212 items into mokken scales (may take some time). scale <- search.normal(acl) # investigate monotonicity for all items in the first scale. monotonicity.list <- check.monotonicity(acl[,scale==1]) # summary of the results summary(monotonicity.list)