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ERIC Number: EJ985879
Record Type: Journal
Publication Date: 2012-Dec
Pages: 21
Abstractor: As Provided
Reference Count: 24
ISSN: ISSN-1076-9986
The Impact of Variability of Item Parameter Estimators on Test Information Function
Zhang, Jinming
Journal of Educational and Behavioral Statistics, v37 n6 p737-757 Dec 2012
The impact of uncertainty about item parameters on test information functions is investigated. The information function of a test is one of the most important tools in item response theory (IRT). Inaccuracy in the estimation of test information can have substantial consequences on data analyses based on IRT. In this article, the major part (called the adjusted term) of the deviation of an estimated test information function from the true test information function due to the uncertainty of item parameters was approximated asymptotically, and a simulation study shows that this approximation captures the difference between the estimated and the true information functions rather well. A real data example shows that the magnitude of an estimated adjusted term can be substantially large when a sample size is relatively small. (Contains 6 tables and 4 figures.)
SAGE Publications. 2455 Teller Road, Thousand Oaks, CA 91320. Tel: 800-818-7243; Tel: 805-499-9774; Fax: 800-583-2665; e-mail:; Web site:
Publication Type: Journal Articles; Reports - Evaluative
Education Level: Elementary Education; Grade 4; Intermediate Grades
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A
Identifiers - Assessments and Surveys: National Assessment of Educational Progress; SAT (College Admission Test)