This function implements the upsilon effect size statistic as described in Lachowicz, Preacher, & Kelley (in press) for mediation.
upsilon(x, mediator, dv, conf.level = 0.95, bootstrap = TRUE,
bootstrap.package = "lavaan", bootstrap.type="ordinary", B = 1000,
boot.data.out=FALSE, ...)x is the independent variable.
mediator is the mediator variable.
dv is the outcome or dependent variable.
conf.level is the desired confidence coefficient (i.e., the complement of the Type I error rate).
TRUE or FALSE regarding if a bootstrap confidence interval should be constructed
The package that will be used for bootstrapping, either lavaan or boot (default is lavaan).
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".
The number of bootstrap replications (1000 is default)
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.
Returns the value of the effect size upsilon for a simple mediation model.
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.
Wen, Z., & Fan, X. (2015). Monotonicity of effect sizes: Questioning kappa-squared as mediation effect size measure. Psychological Methods, 20, 193--203.