TY - JOUR
T1 - A Continuous a-Stratification Index for Item Exposure Control in Computerized Adaptive Testing
AU - Huebner, Alan
AU - Wang, Chun
AU - Daly, Bridget
AU - Pinkelman, Colleen
N1 - Publisher Copyright:
© The Author(s) 2018.
PY - 2018/10/1
Y1 - 2018/10/1
N2 - The method of (Formula presented.) -stratification aims to reduce item overexposure in computerized adaptive testing, as items that are administered at very high rates may threaten the validity of test scores. In existing methods of (Formula presented.) -stratification, the item bank is partitioned into a fixed number of nonoverlapping strata according to the items’ (Formula presented.), or discrimination, parameters. This article introduces a continuous (Formula presented.) -stratification index which incorporates exposure control into the item selection index itself and thus eliminates the need for fixed discrete strata. The new continuous (Formula presented.) -stratification index is compared with existing stratification methods via simulation studies in terms of ability estimation bias, mean squared error, and control of item exposure rates.
AB - The method of (Formula presented.) -stratification aims to reduce item overexposure in computerized adaptive testing, as items that are administered at very high rates may threaten the validity of test scores. In existing methods of (Formula presented.) -stratification, the item bank is partitioned into a fixed number of nonoverlapping strata according to the items’ (Formula presented.), or discrimination, parameters. This article introduces a continuous (Formula presented.) -stratification index which incorporates exposure control into the item selection index itself and thus eliminates the need for fixed discrete strata. The new continuous (Formula presented.) -stratification index is compared with existing stratification methods via simulation studies in terms of ability estimation bias, mean squared error, and control of item exposure rates.
KW - computerized adaptive testing
KW - item exposure control
KW - item response theory
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U2 - 10.1177/0146621618758289
DO - 10.1177/0146621618758289
M3 - Article
C2 - 30237644
AN - SCOPUS:85044377753
SN - 0146-6216
VL - 42
SP - 523
EP - 537
JO - Applied Psychological Measurement
JF - Applied Psychological Measurement
IS - 7
ER -