Description Usage Arguments Value References See Also Examples

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.

1 | ```
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`

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 | ```
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)
``` |

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