#' Nonprobability Sample (sc)
#'
#' This dataset represents a synthetic nonprobability sample generated via
#' Poisson sampling from a finite population constructed from the National
#' Health and Nutrition Examination Survey (NHANES) cycles 1999--2010. It is
#' intended to illustrate the pseudo-weighting methods implemented in the
#' \code{nonprobsampling} package.
#'
#' @format A data frame with 2404 observations and 8 variables:
#' \describe{
#'   \item{psa_level}{Outcome variable: serum prostate-specific antigen level (numeric)}
#'   \item{BMI}{Body mass index category (factor with 4 levels: "Normal", "Overweight", "Obese", "Morbidly Obese")}
#'   \item{race}{Race category (factor with 4 levels: 1 = White, 2 = Black, 3 = Hispanic, 4 = Other)}
#'   \item{agecat}{Age category (factor with 4 levels: 1 = 55--59, 2 = 60--64, 3 = 65--69, 4 = 70+)}
#'   \item{education}{Education level (factor with 5 levels: 1 = Less Than 8 Years, 2 = 8--11 Years, 3 = 12 Years Or Completed High School, 4 = College Graduate, 5 = Postgraduate)}
#'   \item{pros_enlarged}{Prostate enlargement indicator (factor with 2 levels: 0 = No, 1 = Yes)}
#'   \item{comorbidity}{General comorbidity indicator (factor with 2 levels: 0 = No, 1 = Yes)}
#'   \item{diabetes}{Diabetes diagnosis indicator (factor with 2 levels: 0 = No, 1 = Yes)}
#' }
#'
#' @details
#' The dataset has 2,404 complete-case observations, with
#' \code{psa_level} serving as the outcome variable. Auxiliary variables
#' shared with the probability reference surveys \code{sp1} and \code{sp2}
#' are used to construct pseudo-weights aimed at correcting for participation
#' bias.
#'
#' @source
#' Synthetic data generated by the package authors. The underlying finite
#' population was constructed from the National Health and Nutrition
#' Examination Survey (NHANES), 1999--2010 cycles, conducted by the U.S.
#' National Center for Health Statistics (NCHS).
#'
#' @usage data(sc)
#'
#' @examples
#' data(sc)
#' str(sc)
#' summary(sc)
"sc"

