getRSSS function

Compute a Crosswalk Table

getRSSS is a function for generating a raw-score to standard-score crosswalk table.

getRSSS(ipar, theta_grid, is_minscore_0, prior_mu_sigma)

Arguments

• ipar: an item parameter matrix for graded response items. Accepts both a/b and a/d format parameters. Accepts multidimensional item parameters.

• theta_grid: the theta grid to use for numerical integration.

• is_minscore_0: if TRUE, the score of each item begins from 0. if FALSE, the score of each item begins from 1.

• prior_mu_sigma: a named list containing prior distribution parameters. All values must be in the theta metric.

  • mu the prior means
  • sigma the covariance matrix
  • sd the prior standard deviations
  • corr the correlation matrix

Examples

## Free calibration without using anchor

o <- runCalibration(data_asq, technical = list(NCYCLES = 1000))

ipar <- mirt::coef(o, IRTpars = TRUE, simplify = TRUE)$items
items <- getItemNames(data_asq, 2)

getRSSS(
  ipar = ipar[items, ],
  theta_grid = seq(-4, 4, .1),
  is_minscore_0 = TRUE,
  prior_mu_sigma = list(mu = 0, sigma = 1)
)