R/data.R

In NPCDTools: The Nonparametric Classification Methods for Cognitive Diagnosis

#' Q-Matrix from Ozaki (2015)
#'
#' A Q-matrix for 30 multiple-choice items measuring 5 attributes,
#' originally used in Ozaki (2015) to demonstrate structured MC-DINA models.
#' Items 1--10 are single-attribute items with no coded distractors.
#' Items 11--20 have one coded distractor each, and items 21--30 have
#' two or three coded distractors.
#'
#' @format A data frame with 66 rows and 7 columns:
#' \describe{
#'   \item{V1}{Item index (1--30).}
#'   \item{V2}{Option index. For each item, the first row is the key;
#'     subsequent rows are coded distractors.}
#'   \item{V3}{Attribute 1 indicator (0 or 1).}
#'   \item{V4}{Attribute 2 indicator (0 or 1).}
#'   \item{V5}{Attribute 3 indicator (0 or 1).}
#'   \item{V6}{Attribute 4 indicator (0 or 1).}
#'   \item{V7}{Attribute 5 indicator (0 or 1).}
#' }
#'
#' @references
#' Ozaki, K. (2015). DINA models for multiple-choice items with few
#' parameters: Considering incorrect answers. \emph{Applied Psychological
#' Measurement}, \emph{39}, 431--447.
#'
"Q_Ozaki"