check.errors: Check the number of Guttman errors (Gplus) and the number of...
In vandenman/mokken: Conducts Mokken Scale Analysis

Description Usage Arguments Value Author(s) References See Also Examples

Returns a lost containing outlier scores Gplus (number of Guttman errors; Guttman, 1944) and Oplus for each respondent (Zijlstra, van der Ark and Sijtsma, 2007).

1	check.errors(X, returnGplus = TRUE, returnOplus = FALSE)

`X`	matrix or data frame of numeric data containing the responses of `nrow(X)` respondents to `ncol(X)` items. Missing values are not allowed
`returnGplus`	Boolean. If `TRUE` the output contains outlier score Gplus
`returnOplus`	Boolean. If `TRUE` the output contains outlier score Oplus

List. Depending on the values of returnGplus and returnOplus, the output contains outlier score Gplus (the number of Guttman errors) and Oplusfor each respondent

L. A. van der Ark L.A.vanderArk@uva.nl

Guttman, L. (1944) A basis for scaling qualitative data. American Sociological Review, 9, 139-150.

Meijer, R. R. (1994) The number of Guttman errors as a simple and powerful person-fit statistic. Applied Psychological Measurement, 18, 311-314.

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

Zijlstra, W. P., Van der Ark, L. A., and Sijtsma, K. (2007). Outlier detection in test and questionnaire data. Multivariate Behavioral Research, 42, 531-555.

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

data(acl)
Communality <- acl[,1:10]
Gplus <- check.errors(Communality, TRUE, FALSE)$Gplus
Oplus <- check.errors(Communality, FALSE, TRUE)$Oplus

hist(Gplus, breaks = 0:max(Gplus))