Hostname: page-component-6898cfcb55-th4rj Total loading time: 0 Render date: 2026-11-12T02:36:13.434Z Has data issue: false hasContentIssue false

On Maximizing Item Information and Matching Difficulty with Ability

Published online by Cambridge University Press:  01 January 2025

Peter Bickel
Affiliation:
Department of Statistics, University of California at Berkeley
Steven Buyske
Affiliation:
Department of Statistics, Rutgers University
Huahua Chang
Affiliation:
National Board of Medical Examiners
Zhiliang Ying*
Affiliation:
Department of Statistics, Rutgers University
*
Requests for reprints should be sent to Zhiliang Ying, Department of Statistics, Hill Center, Busch Campus, Rutgers University, Piscataway NJ 08854-8019. E-Mail: zying@stat.rutgers.edu

Abstract

An important assumption in IRT model-based adaptive testing is that matching difficulty levels of test items with an examinee's ability makes a test more efficient. According to Lord, “An examinee is measured most effectively when the test items are neither too difficult nor too easy for him”. This assumption is examined and challenged through a class of one-parameter IRT models including those of Rasch and the normal ogive. It is found that for a specific model, the validity of the fundamental assumption is closely related to the so-called van Zwet tail ordering of symmetric distributions. In this connection, the cosine distribution serves as the borderline between those satisfying the assumption and those violating the assumption. Graphic and numerical illustrations are presented to demonstrate the theoretic results.

Information

Type
Articles
Copyright
Copyright © 2001 The Psychometric Society

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable