\inputencoding{latin1}
\HeaderA{sleep}{Student's Sleep Data}{sleep}
\keyword{datasets}{sleep}
\begin{Description}\relax
Data which show the effect of two soporific drugs (increase in hours
of sleep compared to control) on 10 patients.
\end{Description}
\begin{Usage}
\begin{verbatim}sleep\end{verbatim}
\end{Usage}
\begin{Format}\relax
A data frame with 20 observations on 2 variables.
\Tabular{rlll}{
[, 1] & extra & numeric & increase in hours of sleep\\{}
[, 2] & group & factor  & drug given
}
\end{Format}
\begin{Source}\relax
Cushny, A. R. and Peebles, A. R. (1905)
The action of optical isomers: II hyoscines.
\emph{The Journal of Physiology} \bold{32}, 501--510.

Student (1908)
The probable error of the mean.
\emph{Biometrika}, \bold{6}, 20.
\end{Source}
\begin{References}\relax
Scheffé, Henry (1959)
\emph{The Analysis of Variance}.
New York, NY: Wiley.
\end{References}
\begin{Examples}
\begin{ExampleCode}
require(stats)
## Student's paired t-test
t.test(extra ~ group, data = sleep, paired = TRUE)
\end{ExampleCode}
\end{Examples}

