Abstract: An alternative method of finding a common metric for separate calibrations through the use of a common (anchor) set of items is presented. Based on Raju's (1988) method of calculating the area between the two item response functions, this (area-minimization) method minimizes the sum of the squared exact unsigned areas of each of the common items. This new method and five other currently available linking methods are illustrated with an empirical example. For this purpose, data from a calibration administration of two forms of a statewide high school algebra test were used. The need for additional research in this area, especially to establish the degree of congruence among various linking methods, is strongly recommended. (Contains 5 tables and 18 references.) (Author/SLD)

Title: Developing a Common Metric in Item Response Theory: An Area-Minimization Approach.
Author: Raju, Nambury S.; Arenson, Ethan
Note: Paper presented at the Annual Meeting of the National Council on Measurement in Education (New Orleans, LA, April 2-4, 2002).
Page Length: 25
Publication Year: 2002
Document Type: Project Description (141); Conference Paper (150)
Target Audience: Practitioners and Teachers
ERIC Identifier: ED464132
Clearinghouse Identifier: TM033815
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Descriptors: * Item Response Theory; * Test Items

Identifiers: Calibration; *Linking Metrics