mod: Moderation

In medmod: Simple Mediation and Moderation Analysis

Description

Simple mediation analysis

Usage

mod(data, dep, mod, pred, estMethod = "standard", bootstrap = 1000,
  test = TRUE, ci = FALSE, ciWidth = 95, simpleSlopeEst = FALSE,
  simpleSlopePlot = FALSE)

Arguments

data	the data as a data frame
dep	a string naming the dependent variable
mod	a string naming the moderator variable
pred	a string naming the predictor variable
estMethod	'standard' (default), or 'bootstrap', the estimation method to use
bootstrap	a number between 1 and 100000 (default: 1000) specifying the number of samples that need to been drawn in the bootstrap method
test	TRUE (default) or FALSE, provide 'Z' and 'p' values for the mediation estimates
ci	TRUE or FALSE (default), provide a confidence interval for the mediation estimates
ciWidth	a number between 50 and 99.9 (default: 95) specifying the confidence interval width that is used as 'ci'
simpleSlopeEst	TRUE or FALSE (default), provide the estimates of the simple slopes.
simpleSlopePlot	TRUE or FALSE (default), provide a plot of the simple slopes.

Value

A results object containing:

results$mod					a table containing moderation estimates
results$simpleSlope$estimates					a table containing the simple slope estimates
results$simpleSlope$plot					an image
results$modelSyntax					the lavaan syntax used to fit the moderation model

Tables can be converted to data frames with asDF or as.data.frame. For example:

results$mod$asDF

as.data.frame(results$mod)

Examples

set.seed(1234)
X <- rnorm(10)
M <- rnorm(10)
X_M <- X*M
Y <- 0.7*X + 0.1*M + 4.2*X_M + rnorm(10)
dat <- data.frame(X=X, M=M, Y=Y)   

mod(dat, dep = "Y", pred = "X", mod = "M")

#
#  Moderation Estimates                               
#  -------------------------------------------------- 
#             Estimate    SE        Z        p        
#  -------------------------------------------------- 
#    X           0.951    0.0965     9.86    < .001   
#    M          -0.471    0.0923    -5.10    < .001   
#    X:M         4.185    0.1009    41.50    < .001   
#  -------------------------------------------------- 
# 
# 

medmod documentation built on May 1, 2019, 10:25 p.m.