runLinking function

Run Scale Linking

runLinking is a function for obtaining item parameters from the response data in the metric of supplied anchor item parameters.

runLinking(data, method, verbose = FALSE, ...)

Arguments

• data: a PROsetta_data object. See loadData for loading a dataset.

• method: the linking method to use. Accepts:

  • MM for mean-mean method
  • MS for mean-sigma method
  • HB for Haebara method
  • SL for Stocking-Lord method
  • FIXEDPAR for fixed parameter calibration
  • CP for calibrated projection using fixed parameter calibration on the anchor dimension
  • CPLA for linear approximation of calibrated projection. This is identical to 'CP' but uses approximation in runRSSS
  • CPFIXEDDIM for calibrated projection using mean and variance constraints on the anchor dimension

  Linear transformation methods (i.e., MM, MS, HB, SL) are performed with plink in 'plink' package.

• verbose: if TRUE, print status messages. (default = FALSE)

• ...: additional arguments to pass onto mirt in 'mirt' package.

Returns

runLinking returns a list containing the scale linking results.

• constants linear transformation constants. Only available when linear transformation methods were used (i.e., MM, MS, HB, SL).
• ipar_linked item parameters calibrated to the response data, and linked to the metric of anchor item parameters.
• ipar_anchor anchor item parameters used in linking.

Examples

out_link <- runLinking(data_asq, "SL", technical = list(NCYCLES = 1000))
out_link$constants   # transformation constants
out_link$ipar_linked # item parameters linked to anchor
out_link <- runLinking(data_asq, "FIXEDPAR")
out_link$ipar_linked # item parameters linked to anchor