delta_mean_item: Expected bias to item mean

In ddueber/dmacs: Measurement Nonequivalence Effect Size Calculator

Expected bias to item mean

Description

delta_mean_item computes the expected bias in item mean due to measurement nonequivalence.

Usage

delta_mean_item(LambdaR, LambdaF, NuR, NuF, MeanF, VarF, ThreshR = NULL,
  ThreshF = NULL, ThetaR = NULL, ThetaF = NULL,
  categorical = FALSE)

Arguments

LambdaR	is the factor loading of the indicator onto the factor of interest for the reference group.
LambdaF	is the factor loading of the indicator onto the factor of interest for the focal group.
NuR	is the indicator intercept for the reference group.
NuF	is the indicator intercept for the focal group.
MeanF	is the factor mean in the focal group
VarF	is the factor variances in the focal group.
ThreshR	is a vector of thresholds (for categorical indicators) for the reference group. Defaults to NULL for continuous indicators.
ThreshF	is a vector of thresholds (for categorical indicators) for the focal group. Defaults to NULL for continuous indicators.
ThetaR	is the indicator residual variance in the reference group. Defaults to NULL for continuous indicators.
ThetaF	is the indicator residual variance in the focal group. Defaults to NULL for continuous indicators.
categorical	is a Boolean variable declaring whether the variables in the model are ordered categorical. Models in which some variables are categorical and others are continuous are not supported. If no value is provided, categorical defaults to FALSE, although if a vector of thresholds are provided, categorical will be forced to TRUE. A graded response model with probit link (e.g., DWLS in lavaan or WLSMV in Mplus) is used for categorical variables. If you desire for other categorical models (e.g., IRT parameterization) to be supported, e-mail the maintainer.

Details

delta_mean_item is called by dmacs_summary_single, which in turn is called by lavaan_dmacs and mplus_dmacs, which are the only functions in this package intended for casual users

Value

The expected bias in item mean due to measurement nonequivalence in equation 4 of Nye & Drasgow (2011).

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

LambdaF <- 0.74
LambdaR <- 0.76
NuF     <- 1.28
NuR     <- 0.65
MeanF   <- 0.21
VarF    <- 1.76
delta_mean_item(LambdaR, LambdaF, NuR, NuF, MeanF, VarF)

ddueber/dmacs documentation built on Feb. 8, 2023, 11:31 p.m.