sim.slopes: Moderated Simple Slopes

Description Usage Arguments Details Value Author(s) References See Also Examples

Description

Computes the simple slopes for a moderated regression model.

Usage

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sim.slopes(mod, z, zsd = 1, mcz = FALSE)

Arguments

mod

linear model - usually constructed with moderate.lm

z

moderating variable

zsd

Multiple for SD of z; number of SDs from mean to construct simple slopes

mcz

logical whether z is already centered or not in the original data

Details

Constructs the simple slopes for arbitrary values of z (e.g., +/- 1, 2, 3 standard deviations) involved in a moderated multiple regression equation.

Value

A table with the following values for zHigh (Meanz + zsd*SDz), Mean(Meanz), and zLow (Meanz - zsd*SDz):

INT

Intercept of simple slope

Slope

Slope of the simple slope

SE

Standard Error of the slope

LCL, UCL

Lower and Upper confidence limits for slope

Author(s)

Thomas D. Fletcher [email protected]

References

Aiken, L. S., & West, S. G. (1991). Multiple regression: Testing and interpreting interactions. Newbury Park: Sage Publications.

Cohen, J., Cohen, P., West, S. G., & Aiken, L. S. (2003). Applied multiple regression/correlation analysis for the behavioral sciences, 3rd ed. Mahwah, NJ: Lawrence Erlbaum Associates.

See Also

moderate.lm, graph.mod

Examples

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data(tra)
lm.mod1 <- moderate.lm(beliefs, values, attitudes, tra)
ss.mod1 <- sim.slopes(lm.mod1, tra$values)
ss.mod1

QuantPsyc documentation built on May 29, 2017, 10:40 a.m.