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Item characteristic curve (unsigned area) method for DIF detection under item response theory

Research Method · All research methods
Evidence · 1 claim (1 for) · 1 study (1 associational), q1 · 0 of 1 report an effect size · 1 claim rests on one study

Description

The ICC method compares item characteristic curves estimated separately for reference and focal groups, computing the unsigned area between the male and female curves as a DIF index, using a probability index developed by Linn. Item parameters come from Samejima's graded-response model with random MML estimation, with a linear transformation placing groups on a common scale. A randomly split reference-group baseline estimates DIF attributable to sampling variation. The article notes this procedure yields one index per pair of rating categories rather than a simultaneous estimate.

Accounts

  • Item characteristic curve (unsigned area) method for DIF detection under item response theory: The ICC method compares item characteristic curves estimated separately for reference and focal groups, computing the unsigned area between the male and female curves as a DIF index, using a probability index developed by Linn. Item parameters come from Samejima's graded-response model with random MML estimation, with a linear transformation placing groups on a common scale. A randomly split reference-group baseline estimates DIF attributable to sampling variation. The article notes this procedure yields one index per pair of rating categories rather than a simultaneous estimate. (Holweger et al. (1998))

Claims

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Key Sources

  • Holweger, Nancy; Weston, Timothy. (1998). Differential Item Functioning: An Applied Comparison of the Item Characteristic Curve Method with the Logistic Discriminant Function Method. https://eric.ed.gov/?id=ED422362
Page metadata
Field Value
type research-method
id item-characteristic-curve-unsigned-area-method-for-dif-detection-under-item-response-theor
title Item characteristic curve (unsigned area) method for DIF detection under item response theory
description The ICC method compares item characteristic curves estimated separately for reference and focal groups, computing the unsigned area between the male and female curves as a DIF index, using a probability index developed by Linn.
status review
moved_from theory/icc-unsigned-area-dif-method
generated by process:sweep-kinds on 2026-10-10
trust unverified — no one has confirmed this page's content
sources 1 — holweger-1998

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