ieTest: Testing the indirect effect.

In ieTest: Indirect Effects Testing Methods in Mediation Analysis

Testing the indirect effect.

Description

This function takes a vector estimates and a matrix of covariances or a vector of U values to be used in various indirect effect tests. Estimate vectors with three parameters will default to single mediator analysis (or one path of unordered mediation), and five parameters will default to the ordered scenario. Values for the interaction term must be provided for this wrapper. The user can then specify the distribution(s) to be used as well as the test to be performed.

Usage

ieTest(
  test,
  u = NULL,
  V = NULL,
  cov = NULL,
  df = NULL,
  V_0 = 0,
  V1Dist = NULL,
  V2Dist = NULL,
  V3Dist = NULL,
  numSquares = 10,
  upLim = 0.5,
  alpha = 0.05,
  interMult = 1
)

Arguments

test	Denotes the test to be performed. ("maxP", "ps-test", "asq-test", "sobel", "sobel unordered")
u	A vector with the U values to be used in the test. Given priority over estimates, but all must be supplied. Order defined in note.
V	A vector containing the estimates to be used in the test. Must follow same order as u.
cov	A matrix of the covariance matrix of the estimates in V. Must be square with dimensions compatible with V. Must follow same order as u.
df	A vector of the degrees of freedom for the effect estimates. Length of 2 for single mediator, 3 for ordered.
V_0	A vector containing the null values of the estimates to be used in the test. Defaults to zero.
V1Dist	String value specifying the distribution of the estimate of the independent variable on the mediator.
V2Dist	String value specifying the distribution of the second estimate.
V3Dist	String value specifying the distribution of the third estimate (only needed for ordered scenario).
numSquares	The number of squares to be used in the asq-test. Always superseded by upLim.
upLim	The allowed extension, between 0 and 1, for the asq and ps-tests.
alpha	A vector for the asq-test of significance levels to test. A value in the ps-test to control type I error.
interMult	Integer indicating the level of the independent variable to use for the interaction terms.

Value

A p-value or p-value cutoff for the specified test for the indirect effect.

Note

Order of parameters Values must be in the correct order within u, V, and the cov matrix.

Single mediator (or single path in unordered scenarios):
Independent variable to mediator, mediator to response, interaction of independent and mediator.

Ordered mediators:
Independent variable to first mediator, first mediator to second mediator, interaction of independent and first mediator on second mediator, second mediator to response, interaction of independent and second mediator on response.

Combined Unordered Mediator:
Independent variable to first mediator, first mediator to response, interaction of independent and first mediator on response, Independent variable to second mediator, second mediator to response, interaction of independent and second mediator on response.

Examples

ieTest( test = "ps-test", u = c(.015, .02, .998), alpha = 0.05, upLim = 0.5)

ieTest documentation built on April 12, 2025, 1:49 a.m.