Effects of Item Pool Characteristics on Ability Estimate and Item Pool Utilization: A Simulation Study
Abstract
Forming
an item pool for computerized adaptive testing requires a long and demanding process
that may be challenging, both in terms of time and cost. Therefore, one may come
across such questions as ‘How should an optimal item pool be?’ and/or ‘How many
items should exist in an item pool?’ Although research with regard to the features
to exist in an optimal item pool vary, there has been no consensus reached about
how big the item pool size should be. In the current study, the effect of different
item pool size and item distribution on ability estimation and item pool utilization
was analysed. 36 different item pools were generated through SimulCAT software.
Using 1,000 simulees, single session CAT environments were simulated and two different
termination rules were used in the study. Findings of the study indicated that as
the size of the item pool increased to a specific size, the precision of measurement
increased and the number of unused items decreased. By examining the results according
to b parameter, it was found that the
effect of b parameter distribution over
the results decreased.
Keywords
References
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Details
Primary Language
English
Subjects
-
Journal Section
Research Article
Authors
Publication Date
April 30, 2019
Submission Date
December 11, 2017
Acceptance Date
July 12, 2018
Published in Issue
Year 2019 Volume: 34 Number: 2