Implements mean-sigma, mean-mean, Stocking-Lord, and Haebara linking for
dichotomous 2PL-style item parameters. New-form parameters are transformed
onto the reference scale using theta_ref = A * theta_new + B.
Usage
equate_irt_scales(
reference,
new,
method = c("stocking-lord", "haebara", "mean-sigma", "mean-mean"),
theta_grid = seq(-4, 4, length.out = 81)
)
Arguments
- reference
Reference-scale parameters or data.
- new
New-scale parameters or data.
- method
Method used for estimation, linking, or comparison.
- theta_grid
Grid of latent-trait values used for evaluation.
Value
An object of class "eye_irt_equating", stored as a named list, with components "A", "B", "method", "transformed", "reference", "new", "equation". It contains equate IRT scales using anchor item parameters and associated metadata or diagnostics needed to interpret the result.
