ECV_SG {BifactorIndicesCalculator} | R Documentation |
Computes an ECV index for all factors which can be interpreted as the proportion of
common variance of all items which is due to the specific factor;
ECV_SG
should be read 'ECV of a specific factor with respect to the general
factor.' Here,
ECV is computed with respect to the items of the general factor using the specific factor loadings in
the numerator; Stucky and Edelen (2015, p. 199)
refer to this index simply as 'specific-dimension ECV.' Note that ECV_SG
of the general factor
is simply the ECV. In the Excel version of the Bifactor
Indices Calculator (Dueber, 2017), this form of ECV is referred to as 'ECV (S&E).'
ECV_SG
is called by bifactorIndices
and the various convenience functions
for exploratory models and/or Mplus output,
which are the only functions in this package intended for casual users.
ECV_SG(Lambda)
Lambda |
is a matrix of factor loadings. Be sure that all factors have the same variance before calling this function. |
A vector of ECVs for all factors
Dueber, D. M. (2017). Bifactor Indices Calculator: A Microsoft Excel-based tool to calculate various indices relevant to bifactor CFA models. doi: 10.13023/edp.tool.01
Stucky, B. D., & Edelen, M. O. (2015). Using hierarchical IRT models to create unidimensional measures from multidimensional data. In S. P. Reise & D. A. Revicki (Eds.), Handbook of item response theory modeling: Applications to typical performance assessment (pp.183-206). New York: Routledge.
ECV_SS
, ECV_GS
, bifactorIndices
Lambda <- matrix(c(.82, .10, 0, 0, .77, .35, 0, 0, .79, .32, 0, 0, .66, .39, 0, 0, .51, 0, .71, 0, .56, 0, .43, 0, .68, 0, .13, 0, .60, 0, .50, 0, .83, 0, 0, .47, .60, 0, 0, .27, .78, 0, 0, .28, .55, 0, 0, .75), ncol = 4, byrow = TRUE) colnames(Lambda) <- c("General", "SF1", "SF2", "SF3") ECV_GS(Lambda)