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Resolving Equating Inconsistencies: How the Man With Four Watches Decides What Time It Is MAPP

Author(s):
Livingston, Samuel A.; Antal, Judit
Publication Year:
2008
Report Number:
RM-08-06
Source:
ETS Research Memorandum
Document Type:
Report
Subject/Key Words:
Measure of Academic Proficiency and Progress (MAPP), Academic Profile, Test Equating

Abstract

Four new forms of a test were equated to each other and to a reference form in a complex design incorporating 7 separate equating links. Four paths linked each new form to the reference form, and each path produced a different score conversion. These inconsistencies were resolved by a procedure applied separately at each score level, treating each equating as a simple additive increment. Imposing constraints on the values of those increments led to a system of seven equations in 7 unknowns. Solving the system of equations produced a set of adjusted increments, so that the 4 paths linking any form to the reference form yielded the same score conversion.

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