\HeaderA{morley}{Michaelson-Morley Speed of Light Data}{morley}
\keyword{datasets}{morley}
\begin{Description}\relax
The classical data of Michaelson and Morley on the speed of light.
The data consists of five experiments, each consisting of 20
consecutive \sQuote{runs}.  The response is the speed of light
measurement, suitably coded.
\end{Description}
\begin{Usage}
\begin{verbatim}morley\end{verbatim}
\end{Usage}
\begin{Format}\relax
A data frame contains the following components:
\describe{
\item[\code{Expt}] The experiment number, from 1 to 5.
\item[\code{Run}] The run number within each experiment.
\item[\code{Speed}] Speed-of-light measurement.
}
\end{Format}
\begin{Details}\relax
The data is here viewed as a randomized block experiment with
\sQuote{experiment} and \sQuote{run} as the factors.  \sQuote{run} may
also be considered a quantitative variate to account for linear (or
polynomial) changes in the measurement over the course of a single
experiment.
\end{Details}
\begin{Source}\relax
A. J. Weekes (1986)
\emph{A Genstat Primer}.
London: Edward Arnold.
\end{Source}
\begin{Examples}
\begin{ExampleCode}
require(stats); require(graphics)
morley$Expt <- factor(morley$Expt)
morley$Run <- factor(morley$Run)

xtabs(~ Expt + Run, data = morley)# 5 x 20 balanced (two-way)
plot(Speed ~ Expt, data = morley,
     main = "Speed of Light Data", xlab = "Experiment No.")
fm <- aov(Speed ~ Run + Expt, data = morley)
summary(fm)
fm0 <- update(fm, . ~ . - Run)
anova(fm0, fm)
\end{ExampleCode}
\end{Examples}

