R/huttenlocher1991-package.R

In tjmahr/huttenlocher1991: Vocabulary growth in 22 infants (Huttenlocher et al., 1991)

## usethis namespace: start
## usethis namespace: end
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#' Vocabulary growth for 22 toddlers
#'
#' A dataset of children's vocabulary over time.
#'
#' @format A data frame with 126 rows and 9 variables:
#' \describe{
#'   \item{id}{child id. there are 22 unique children}
#'   \item{mom_speak}{tbd}
#'   \item{sex}{tbd}
#'   \item{group}{tbd}
#'   \item{log_mom}{tbd}
#'   \item{age}{age in months}
#'   \item{vocab}{vocabulary, type tbd}
#'   \item{age_12}{age in months centered at 12 months}
#'   \item{age_12_sq}{age in months squared centered at 12 months}
#' }
#' @references Huttenlocher, J., Haight, W., Bryk, A., Seltzer, M., & Lyons, T.
#'   (1991). Early vocabulary growth: relation to language input and gender.
#'   Developmental psychology, 27(2), 236.
#'   \url{https://doi.org/10.1037/0012-1649.27.2.236}
#' @source Downloaded from
#'   \url{https://ssicentral.com/index.php/products/hlm-general/hlm-examples/}
"vocab_growth"