trtools: Miscellaneous Tools for Teaching Statistics

#' Survey of the density of nesting birds. 
#'
#' A two-phase sampling design for the density of nesting birds. In the first phase a sample was selected from 2130 plots. A rapid search method was used to obtain an approximate count of the number of nests in these plots. Then a sample of plots was selected from this first sample, and the number of nests was counted in these plots using an intensive method.
#'
#' @format A data frame 201 observations and two variables:
#' \describe{
#'    \item{rapid:}{number of birds counted using a rapid search method}
#'    \item{intense:}{number of nests counted using an intensive method}
#' }
#' 
#' @note That data are from Lohr (2010), reconstructed from summary statistics reported by Bart and Earnst (2002). 
#' 
#' @source Bart, J. & Earnst, S. (2002). Double-sampling to estimate density and population trends in birds. \emph{The Auk}, \emph{119}, 36--45.
#' 
#' Lohr, S. L. (2010). \emph{Sampling: Design and analysis} (2nd edition). Boston: Brooks/Cole.
#' 
"shorebirds"