dmacs (version 0.1.0)

lavaan_dmacs: Summary of measurement nonequivalence effects

Description

lavaan_dmacs returns a summary of measurement non-equivalence effects given a fitted multigroup lavaan object.

Usage

lavaan_dmacs(fit, RefGroup = 1, dtype = "pooled", ...)

Arguments

fit

is a fitted lavaan multi-group object. Only CFA models are supported, and be sure to have an anchor item.

RefGroup

can be the name of the reference group (as a string), or the index of the reference group (as a number). RefGroup defaults to the first group if no value is provided. It is strongly recommended to provide the reference group as a string, since group names in data are often ordered by their appearance in the data, not alphabetically.

dtype

described the pooling of standard deviations for use in the denominator of the dmacs effect size. Possibilities are "pooled" for pooled standard deviations, or "glass" for always using the standard deviation of the reference group.

...

other parameters to be used in functions that lavaan_dmacs calls, most likely stepsize for the item_dmacs and delta_mean_item functions.

Value

A list, indexed by group, of lists of measurement nonequivalence effects from Nye and Drasgow (2011), including dmacs, expected bias in the mean score by item, expected bias in the mean total score, and expected bias in the variance of the total score. Expected bias in the variance of the total score is only supplied for unidimensional models in the current version of this package

References

Nye, C. & Drasgow, F. (2011). Effect size indices for analyses of measurement equivalence: Understanding the practical importance of differences between groups. Journal of Applied Psychology, 96(5), 966-980.

Examples

# NOT RUN {
HS.model <- '  visual  =~ x1 + x2 + x3
               textual =~ x4 + x5 + x6
               speed   =~ x7 + x8 + x9 '
fit <- lavaan::cfa(HS.model,
                  data = lavaan::HolzingerSwineford1939,
                  group = "school")
lavaan_dmacs(fit, RefGroup = "Pasteur")


# }