Equating without an anchor for non-equivalent groups
of examinees
N. T. Longford
Abstract
An equating procedure for a testing program with evolving distribution
of examinee profiles is developed. No anchor is available because the original
scoring scheme was based on expert judgement of the item difficulties.
Pairs of examinees from two administrations are formed by matching
on coarsened propensity scores derived from a set of background variables.
These two subsets of scores are then equated, treating the associated sets
of test performances as equivalent. The method is applied to the scores
in two years of a testing program for admission to tertiary education.
In Journal of Educational and Behavioral Statistics 40,
227-253, 2015.