% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/cronbachs_alpha.R
\name{cronbachs_alpha}
\alias{cronbachs_alpha}
\title{Cronbach's Alpha for Items or Scales}
\usage{
cronbachs_alpha(x)
}
\arguments{
\item{x}{A matrix or a data frame.}
}
\value{
The Cronbach's Alpha value for \code{x}.
}
\description{
Compute various measures of internal consistencies
   for tests or item-scales of questionnaires.
}
\details{
The Cronbach's Alpha value for \code{x}. A value closer to 1
   indicates greater internal consistency, where usually following
   rule of thumb is applied to interpret the results:
   \ifelse{html}{\out{&alpha;}}{\eqn{\alpha}{alpha}} < 0.5 is unacceptable,
   0.5 < \ifelse{html}{\out{&alpha;}}{\eqn{\alpha}{alpha}} < 0.6 is poor,
   0.6 < \ifelse{html}{\out{&alpha;}}{\eqn{\alpha}{alpha}} < 0.7 is questionable,
   0.7 < \ifelse{html}{\out{&alpha;}}{\eqn{\alpha}{alpha}} < 0.8 is acceptable,
   and everything > 0.8 is good or excellent.
}
\examples{
data(mtcars)
x <- mtcars[, c("cyl", "gear", "carb", "hp")]
cronbachs_alpha(x)
}
\references{
Bland, J. M., \& Altman, D. G. Statistics notes: Cronbach's alpha. BMJ 1997;314:572. 10.1136/bmj.314.7080.572
}
