Fachgruppe für Methoden und Evaluation - Universität Bamberg

Fr., 23.09., Einzelbeitrag, 10.40-11.00 Uhr, Kapelle M3/126N (K)
A framework for test equating based on the concepts of equity and causal
effects
Safir Yousfi
German Federal Employment
Agency
Psychological Research
and Development
A formal approach to test equating relying on the
concept of equity is proposed. It is shown that other
equating criteria discussed in the literature (equal
reliability, equal construct, symmetry, population
invariance) are either inappropriate or implications of
equity. It is argued that Lord’s equity theorem does not
justify serious doubts on the usefulness of the equity
concept, in spite of the fact that there is no way to
circumvent the theorem by refined techniques like local
equating. Equating could be paraphrased as a
technique of generating transformed scores for which
the choice of the test form has no (substantial) causal
effect for each individual. The result of this
transformation might depend not only on the raw score
but also on covariates and random noise. The
relevance of the counterfactual perspective of causality
for analyzing equating designs and techniques is
outlined, as well as benefits of equating concepts and
techniques for the analysis of causal effects.
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