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Last data update: 2014.03.03

R: Tests the five Berry, Golder and Milton (2012) Interactive...

BGMtest

R Documentation

Tests the five Berry, Golder and Milton (2012) Interactive Hypothesis

Description

This function tests the five hypotheses that Berry, Golder and Milton identify as important when two quantitative variables are interacted in a linear model.

Usage

BGMtest(obj, vars, digits = 3, level = 0.05, two.sided=T)

Arguments

`obj`	An object of class `lm`.
`vars`	A vector of two variable names giving the two quantitative variables involved in the interaction. These variables must be involved in one, and only one, interaction.
`digits`	Number of digits to be printed in the summary.
`level`	Type I error rate for the tests.
`two.sided`	Logical indicating whether the tests should be two-sided (if `TRUE`, the default) or one-sided (if `FALSE`).

Value

A matrix giving five t-tests.

Author(s)

Dave Armstrong (UW-Milwaukee, Department of Political Science)

Examples

library(car)
data(Duncan)
mod <- lm(prestige ~ income*education + type, data=Duncan)
BGMtest(mod, c("income", "education"))

Results


R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

> library(DAMisc)
Loading required package: car
Loading required package: effects

Attaching package: 'effects'

The following object is masked from 'package:car':

    Prestige

> png(filename="/home/ddbj/snapshot/RGM3/R_CC/result/DAMisc/BGMtest.Rd_%03d_medium.png", width=480, height=480)
> ### Name: BGMtest
> ### Title: Tests the five Berry, Golder and Milton (2012) Interactive
> ###   Hypothesis
> ### Aliases: BGMtest
> 
> ### ** Examples
> 
> library(car)
> data(Duncan)
> mod <- lm(prestige ~ income*education + type, data=Duncan)
> BGMtest(mod, c("income", "education"))
             est    se      t p-value
P(X|Zmin)  0.815 0.135  6.024 0.000  
P(X|Zmax)  0.326 0.156  2.087 0.043  
P(Z|Xmin)  0.603 0.165  3.652 0.001  
P(Z|Xmax)  0.214 0.126  1.696 0.098  
P(XZ)     -0.005 0.003 -2.081 0.044  
> 
> 
> 
> 
> 
> dev.off()
null device 
          1 
>