ERIC Number: EJ1129534
Record Type: Journal
Publication Date: 2017
Pages: 32
Abstractor: As Provided
ISBN: N/A
ISSN: ISSN-1530-5058
EISSN: N/A
Effects of Differential Item Functioning on Examinees' Test Performance and Reliability of Test
Lee, Yi-Hsuan; Zhang, Jinming
International Journal of Testing, v17 n1 p23-54 2017
Simulations were conducted to examine the effect of differential item functioning (DIF) on measurement consequences such as total scores, item response theory (IRT) ability estimates, and test reliability in terms of the ratio of true-score variance to observed-score variance and the standard error of estimation for the IRT ability parameter. The objective was to provide bounds of the likely DIF effects on these measurement consequences. Five factors were manipulated: test length, percentage of DIF items per form, item type, sample size, and level of group ability difference. Results indicate that the greatest DIF effect was less than 2 points on the 0 to 60 total score scale and about 0.15 on the IRT ability scale. DIF had a limited effect on the ratio of true-score variance to observed-score variance, but its influence on the standard error of estimation for the IRT ability parameter was evident for certain ability values.
Descriptors: Test Bias, Test Reliability, Performance, Scores, Item Response Theory, Ability, Computation, True Scores, Error of Measurement, Test Length, Test Items, Sample Size, Differences
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Publication Type: Journal Articles; Reports - Research
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A
Grant or Contract Numbers: N/A