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sjstats (version 0.7.1)

std_beta: Standardized beta coefficients and CI of linear and mixed models

Description

Returns the standardized beta coefficients, std. error and confidence intervals of a fitted linear (mixed) models.

Usage

std_beta(fit, type = "std")

Arguments

fit
Fitted linear (mixed) model of class lm or merMod (\href{https://CRAN.R-project.org/package=#1}{\pkg{#1}}lme4lme4 package).
type
If fit is of class lm, normal standardized coefficients are computed by default. Use type = "std2" to follow Gelman's (2008) suggestion, rescaling the estimates by deviding them by two standard deviations, so resulting coefficients are directly comparable for untransformed binary predictors.

Value

A tibble with term names, standardized beta coefficients, standard error and confidence intervals of fit.

Details

“Standardized coefficients refer to how many standard deviations a dependent variable will change, per standard deviation increase in the predictor variable. Standardization of the coefficient is usually done to answer the question of which of the independent variables have a greater effect on the dependent variable in a multiple regression analysis, when the variables are measured in different units of measurement (for example, income measured in dollars and family size measured in number of individuals).” (Source: Wikipedia)

References

Wikipedia: Standardized coefficient Gelman A. 2008. Scaling regression inputs by dividing by two standard deviations. Statistics in Medicine 27: 2865–2873. http://www.stat.columbia.edu/~gelman/research/published/standardizing7.pdf

Examples

Run this code
# fit linear model
fit <- lm(Ozone ~ Wind + Temp + Solar.R, data = airquality)
# print std. beta coefficients
std_beta(fit)

# print std. beta coefficients and ci, using
# 2 sd and center binary predictors
std_beta(fit, type = "std2")

# std. beta for mixed models
library(lme4)
fit1 <- lmer(Reaction ~ Days + (Days | Subject), sleepstudy)
std_beta(fit)

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