## ----include=FALSE------------------------------------------------------- library("knitr") options(prompt="R> ", continue = "+ ", width = 75, useFancyQuotes = FALSE) opts_chunk$set(fig.path = "knitr-figures/figure-", fig.align = "center", fig.lp = "fig:", fig.pos = "t", tidy = FALSE) render_sweave() # use Sweave environments set_header(highlight = "") # do not use the Sweave.sty package ## ----eval=FALSE---------------------------------------------------------- # install.packages("robmed") ## ----results='hide', message=FALSE, warning=FALSE------------------------ library("robmed") data("BSG2014") ## ------------------------------------------------------------------------ keep <- c("ValueDiversity", "TaskConflict", "TeamCommitment", "TeamScore", "SharedLeadership", "AgeDiversity", "GenderDiversity", "ProceduralJustice", "InteractionalJustice", "TeamPerformance") summary(BSG2014[, keep]) ## ----eval=FALSE---------------------------------------------------------- # TeamCommitment ~ m(TaskConflict) + ValueDiversity ## ----eval=FALSE---------------------------------------------------------- # TeamScore ~ serial_m(TaskConflict, TeamCommitment) + ValueDiversity ## ----eval=FALSE---------------------------------------------------------- # TeamPerformance ~ parallel_m(ProceduralJustice, InteractionalJustice) + # SharedLeadership + covariates(AgeDiversity, GenderDiversity) ## ------------------------------------------------------------------------ seed <- 20150601 ## ------------------------------------------------------------------------ f_simple <- TeamCommitment ~ m(TaskConflict) + ValueDiversity ## ----cache=TRUE---------------------------------------------------------- set.seed(seed) robust_boot_simple <- test_mediation(f_simple, data = BSG2014, robust = TRUE) set.seed(seed) ols_boot_simple <- test_mediation(f_simple, data = BSG2014, robust = FALSE) ## ----summary, fig.width=5, fig.height=4.5, out.width="0.67\\textwidth", fig.cap="Diagnostic plot of the regression weights from the robust bootstrap procedure of \\citet{alfons22a}.", fig.pos="b!"---- summary(robust_boot_simple) ## ----eval=FALSE---------------------------------------------------------- # weight_plot(robust_boot_simple) + # scale_color_manual("", values = c("black", "#00BFC4")) + # theme(legend.position = "top") ## ------------------------------------------------------------------------ summary(ols_boot_simple, type = "data") ## ------------------------------------------------------------------------ coef(robust_boot_simple) confint(robust_boot_simple) ## ------------------------------------------------------------------------ coef(ols_boot_simple, type = "data") confint(ols_boot_simple, type = "data") ## ------------------------------------------------------------------------ coef(robust_boot_simple, parm = "Indirect") confint(robust_boot_simple, parm = "Indirect") ## ----cache=TRUE---------------------------------------------------------- p_value(robust_boot_simple, parm = "Indirect") p_value(ols_boot_simple, parm = "Indirect") ## ------------------------------------------------------------------------ boot_list <- list("OLS bootstrap" = ols_boot_simple, "ROBMED" = robust_boot_simple) ## ----density, fig.width=5, fig.height=3.75, out.width="0.7\\textwidth", fig.cap="Density plot of the bootstrap distributions of the indirect effect, obtained via the OLS bootstrap and the robust bootstrap procedure of \\citet{alfons22a}. The vertical lines indicate the the respective point estimates of the indirect effect and the shaded areas represent the confidence intervals.", fig.pos="t!"---- density_plot(boot_list) ## ----ci, fig.width=6, fig.height=4, out.width="0.85\\textwidth", fig.cap="Point estimates and 95\\% confidence intervals for selected effects in the mediation model, estimated via the OLS bootstrap and the robust bootstrap procedure of \\citet{alfons22a}.", fig.pos="t!"---- ci_plot(boot_list, parm = c("a", "b", "Direct", "Indirect")) ## ----ellipse, fig.width=5, fig.height=3.5, out.width="0.68\\textwidth", fig.cap="Diagnostic plot with tolerance ellipses for the OLS bootstrap and the robust bootstrap procedure of \\citet{alfons22a}.", fig.pos="b!"---- ellipse_plot(boot_list, horizontal = "ValueDiversity", vertical = "TaskConflict") ## ----ellipse-custom, fig.width=5, fig.height=3.5, out.width="0.68\\textwidth", fig.cap="Customized diagnostic plot with tolerance ellipses but without regression lines for the OLS bootstrap and the robust bootstrap procedure of \\citet{alfons22a}."---- setup <- setup_ellipse_plot(boot_list, horizontal = "ValueDiversity", vertical = "TaskConflict") ggplot() + geom_path(aes(x = x, y = y, color = Method), data = setup$ellipse) + geom_point(aes(x = x, y = y, fill = Weight), data = setup$data, shape = 21) + scale_fill_gradient(limits = 0:1, low = "white", high = "black") + labs(x = setup$horizontal, y = setup$vertical) ## ------------------------------------------------------------------------ f_serial <- TeamScore ~ serial_m(TaskConflict, TeamCommitment) + ValueDiversity ## ----cache=TRUE---------------------------------------------------------- set.seed(seed) robust_boot_serial <- test_mediation(f_serial, data = BSG2014, level = 0.9, robust = TRUE) set.seed(seed) ols_boot_serial <- test_mediation(f_serial, data = BSG2014, level = 0.9, robust = FALSE) ## ------------------------------------------------------------------------ robust_boot_serial ols_boot_serial ## ----weight, fig.width=5, fig.height=5.5, out.width="0.7\\textwidth", fig.cap="Diagnostic plot of the regression weights from the robust bootstrap procedure of \\citet{alfons22a} in the example for a serial multiple mediator model."---- weight_plot(robust_boot_serial) + scale_color_manual("", values = c("black", "#00BFC4")) + theme(legend.position = "top") ## ------------------------------------------------------------------------ f_parallel <- TeamPerformance ~ parallel_m(ProceduralJustice, InteractionalJustice) + SharedLeadership + covariates(AgeDiversity, GenderDiversity) ## ----cache=TRUE---------------------------------------------------------- set.seed(seed) robust_boot_parallel <- test_mediation(f_parallel, data = BSG2014, robust = TRUE) set.seed(seed) ols_boot_parallel <- test_mediation(f_parallel, data = BSG2014, robust = FALSE) ## ------------------------------------------------------------------------ robust_boot_parallel ols_boot_parallel ## ----ellipse-partial, fig.width=5, fig.height=3.875, out.width="0.7\\textwidth", fig.cap="Diagnostic plot with a tolerance ellipse for partial residuals in a multiple parallel mediator model."---- ellipse_plot(robust_boot_parallel, horizontal = "SharedLeadership", vertical = "TeamPerformance", partial = TRUE) ## ----cache=TRUE---------------------------------------------------------- set.seed(seed) test_mediation(f_parallel, data = BSG2014, contrast = "absolute") ## ------------------------------------------------------------------------ retest(robust_boot_parallel, contrast = "absolute") ## ------------------------------------------------------------------------ summary(robust_boot_serial, plot = FALSE) ## ----summary-parallel, fig.width=5, fig.height=5.5, out.width="0.7\\textwidth", fig.cap="Diagnostic plot of the regression weights from the robust bootstrap procedure of \\citet{alfons22a} in the example for a parallel multiple mediator model.", fig.pos="t!"---- summary(robust_boot_parallel)