Person location estimation (old version) — RIestThetasOLD • easyRasch

NOTE: Does not work with dichotomous data

Usage

RIestThetasOLD(
  dfin,
  itemParams,
  model = "PCM",
  method = "WL",
  theta_range = c(-7, 7)
)

Arguments

dfin: Dataframe with response data only (no demographics etc), items as columns
itemParams: Optional item (threshold) location matrix
model: Rasch model to use (currently only default PCM works)
method: Estimation method (defaults to "WL")
theta_range: Range of theta (person location) values

Details

Outputs a vector of person locations, one for each row in the dataframe.

Uses thetaEst function from catR package to estimate person locations (thetas) for a dataframe with item data as columns and persons as rows. Defaults to use WL estimation (lower bias than ML) and PCM. See ?thetaEst for options available.

A version for multi-core processing is available as RIestThetasOLD2().