epmr: Tools for Educational and Psychological Measurement

#' BDI-II Item Correlation and Covariance Matrices
#'
#' A list containing correlation and covariance matrices for the 21 items
#' on the BDI-II, as reported in Table 2 of Whisman, Perez, and Ramel (2000).
#' Data come from an administration of the BDI-II to 576 undergraduate students.
#' Item labels are also provided.
#'
#' The correlation matrix is in BDI$R and the covariance matrix is in BDI$S.
#' The row and column names of each matrix are abbreviations of the
#' BDI-II item labels. The full labels, included in BDI$labels, are
#' \enumerate{
#'  \item Sadness
#'  \item Pessimism
#'  \item Past Failure
#'  \item Loss of Pleasure
#'  \item Guilty Feelings
#'  \item Punishment Feelings
#'  \item Self-Dislike
#'  \item Self-Criticalness
#'  \item Suicidal Thoughts
#'  \item Crying
#'  \item Agitation
#'  \item Loss of Interest
#'  \item Indecisiveness
#'  \item Worthlessness
#'  \item Loss of Energy
#'  \item Changes in Sleep
#'  \item Irritability
#'  \item Changes in Apetite
#'  \item Concentration Difficulty
#'  \item Tiredness or Fatigue
#'  \item Loss of Interest in Sex
#'}
#'
#' @format A list containing two matrices, each with 21 rows and 21 columns
#' @source Whisman, M. A., Perez, J. E., and Ramel, W. (2000). Factor structure of
#' the Beck Depression Inventory - Second Edition (BDI-II) in a student sample.
#' Journal of Clinical Psychology, 56(4), 545-551.
"BDI"