upsilon: This function implements the upsilon effect size statistic as described in Lachowicz, Preacher, & Kelley (in press) for mediation.

Description

This function implements the upsilon effect size statistic as described in Lachowicz, Preacher, & Kelley (in press) for mediation.

Usage

upsilon(x, mediator, dv, conf.level = 0.95, bootstrap = TRUE, 
bootstrap.package = "lavaan", bootstrap.type="ordinary", B = 1000,
boot.data.out=FALSE, ...)

Value

Returns the value of the effect size upsilon for a simple mediation model.

Arguments

x: x is the independent variable.
mediator: mediator is the mediator variable.
dv: dv is the outcome or dependent variable.
conf.level: conf.level is the desired confidence coefficient (i.e., the complement of the Type I error rate).
bootstrap: TRUE or FALSE regarding if a bootstrap confidence interval should be constructed
bootstrap.package: The package that will be used for bootstrapping, either lavaan or boot (default is lavaan).
bootstrap.type: The type of bootstrap confidence interval. If bootstrap.package = ``lavaan'', this can be either "ordinary" or"bollen.stine" (default is "ordinary"). If bootstrap.package = ``boot'', "normal", "basic", "student", "perc", or "bca" CIs (default is "perc".
B: The number of bootstrap replications (1000 is default)
boot.data.out: TRUE or FALSE regarding if bootstrap data is returned with function output (only available if bootstrap.boot = TRUE).
...: Allows specifictions for functions that are used within this function.

Author

Lachowicz Mark J. Lachowicz (Vanderbilt University; Mark.J.Lachowicz@Vanderbilt.edu)

References

Lachowicz, M. J., Preacher, K. J., & Kelley, K. (in press). A novel measure of effect size for mediation analysis. Psychological Methods, X, X--X.

Preacher, K. J., & Kelley, K. (2011). Effect size measures for mediation models: quantitative strategies for communicating indirect effects. Psychological Methods, 16, 93--115.