equi-package: equi: A package for equipercentile equating

In twolodzko/equi: equi: Equipercentile Equating

Description

Package for equipercentile equating in Equivalent Groups (EG), Single Group (SG) and Nonequivalent groups with Anchor Test with Chained Equating (NEAT-CE) designs.

Details

The process of observed-score equating consists of several steps: (1) presmoothing, (2) estimating the score probabilities, (3) continuization (or postsmoothing), (4) computing the equating function, and (5) evaluating the equating results and computing accuracy measures (von Davier, 2011; von Davier, Holland & Thayer, 2004). The steps (1)-(3) are implemented with function smoothtab, step (4) with function equi, and step (5) with function see for bootstrap-based Standard Error of Equating estimation.

Equipercentile equting function of scale X to scores of scale Y can be defined as follows:

equi_Y(x) = F^{-1}_Y[F_X(x)]

where Fx ia a cumulative distribution function of X, and Fy is a cumulative distribution function of Y. For the equating function to be symmetric, Fx and Fy need to be continuized so their distribution is transformed from discrete into continous cumulative distribution function. In this package, Gaussian Kernel postsmoothing could be used for this pourpose (von Davier, Holland & Thayer, 2004).

This package was desined during a research project by Wołodźko, Kondratek & Szaleniec (2014).

twolodzko/equi documentation built on Nov. 11, 2020, 4:04 p.m.