DTF_graph: Expected bias in test score

In ddueber/dmacs: Measurement Nonequivalence Effect Size Calculator

Expected bias in test score

Description

DTF_graph produces a graph of expected total score or of expected bias in total score based on item parameters in the reference group and based on item parameters in the focal group.

Usage

DTF_graph(LambdaR, LambdaF, NuR, NuF, RefGroup, FocGroup, ThreshR = NULL,
  ThreshF = NULL, ThetaR = NULL, ThetaF = NULL,
  categorical = FALSE, minEta = -3, maxEta = 3,
  GraphType = "Scores")

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.
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.
minEta	is the minimum factor score to be considered. Defaults to -3.
maxEta	is the maximum factor score to be considered. Defaults to -3.
MeanF	is the factor mean in the focal group
VarF	is the factor variances in the focal group.

Details

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

Value

A graph of expected total score or bias in expected total score due to measurement nonequivalence, per 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 <- matrix(c(1.00, 0.74,  1.14, 0.92), ncol = 1)
LambdaR <- matrix(c(1.00, 0.76,  1.31, 0.98), ncol = 1)
NuF     <- c(0.00, 1.28, -0.82, 0.44)
NuR     <- c(0.00, 0.65, -0.77, 0.47)
DTF_graph(LambdaR, LambdaF, NuR, NuF)

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