@article {73,
	title = {Controlling item exposure and test overlap on the fly in computerized adaptive testing},
	journal = {British Journal of Mathematical and Statistical Psychology},
	volume = {61},
	number = {2},
	year = {2008},
	note = {Chen, Shu-YingLei, Pui-WaLiao, Wen-HanResearch Support, Non-U.S. Gov{\textquoteright}tEnglandThe British journal of mathematical and statistical psychologyBr J Math Stat Psychol. 2008 Nov;61(Pt 2):471-92. Epub 2007 Jul 23.},
	month = {Nov},
	pages = {471-92},
	edition = {2007/07/26},
	abstract = {This paper proposes an on-line version of the Sympson and Hetter procedure with test overlap control (SHT) that can provide item exposure control at both the item and test levels on the fly without iterative simulations. The on-line procedure is similar to the SHT procedure in that exposure parameters are used for simultaneous control of item exposure rates and test overlap rate. The exposure parameters for the on-line procedure, however, are updated sequentially on the fly, rather than through iterative simulations conducted prior to operational computerized adaptive tests (CATs). Unlike the SHT procedure, the on-line version can control item exposure rate and test overlap rate without time-consuming iterative simulations even when item pools or examinee populations have been changed. Moreover, the on-line procedure was found to perform better than the SHT procedure in controlling item exposure and test overlap for examinees who take tests earlier. Compared with two other on-line alternatives, this proposed on-line method provided the best all-around test security control. Thus, it would be an efficient procedure for controlling item exposure and test overlap in CATs.},
	keywords = {*Decision Making, Computer-Assisted, *Models, Psychological, Humans},
	isbn = {0007-1102 (Print)0007-1102 (Linking)},
	author = {Chen, S-Y. and Lei, P. W. and Liao, W. H.}
}
@article {2120,
	title = {Investigating item exposure control on the fly in computerized adaptive testing},
	journal = {Psychological Testing},
	volume = {55},
	year = {2008},
	pages = {1-32},
	author = {Wu, M.-L. and Chen, S-Y.}
}
@article {584,
	title = {Item exposure control in a-stratified computerized adaptive testing},
	journal = {Psychological Testing},
	volume = {55},
	year = {2008},
	pages = {793-811},
	author = {Jhu, Y.-J., and Chen, S-Y.}
}
@article {71,
	title = {Predicting item exposure parameters in computerized adaptive testing},
	journal = {British Journal of Mathematical and Statistical Psychology},
	volume = {61},
	number = {1},
	year = {2008},
	note = {Chen, Shu-YingDoong, Shing-HwangResearch Support, Non-U.S. Gov{\textquoteright}tEnglandThe British journal of mathematical and statistical psychologyBr J Math Stat Psychol. 2008 May;61(Pt 1):75-91.},
	month = {May},
	pages = {75-91},
	edition = {2008/05/17},
	abstract = {The purpose of this study is to find a formula that describes the relationship between item exposure parameters and item parameters in computerized adaptive tests by using genetic programming (GP) - a biologically inspired artificial intelligence technique. Based on the formula, item exposure parameters for new parallel item pools can be predicted without conducting additional iterative simulations. Results show that an interesting formula between item exposure parameters and item parameters in a pool can be found by using GP. The item exposure parameters predicted based on the found formula were close to those observed from the Sympson and Hetter (1985) procedure and performed well in controlling item exposure rates. Similar results were observed for the Stocking and Lewis (1998) multinomial model for item selection and the Sympson and Hetter procedure with content balancing. The proposed GP approach has provided a knowledge-based solution for finding item exposure parameters.},
	keywords = {*Algorithms, *Artificial Intelligence, Aptitude Tests/*statistics \& numerical data, Diagnosis, Computer-Assisted/*statistics \& numerical data, Humans, Models, Statistical, Psychometrics/statistics \& numerical data, Reproducibility of Results, Software},
	isbn = {0007-1102 (Print)0007-1102 (Linking)},
	author = {Chen, S-Y. and Doong, S. H.}
}
@article {247,
	title = {Comparing methods of assessing differential item functioning in a computerized adaptive testing environment},
	journal = {Journal of Educational Measurement},
	volume = {43},
	number = {3},
	year = {2006},
	pages = {245-264},
	publisher = {Blackwell Publishing: United Kingdom},
	abstract = {Mantel-Haenszel and SIBTEST, which have known difficulty in detecting non-unidirectional differential item functioning (DIF), have been adapted with some success for computerized adaptive testing (CAT). This study adapts logistic regression (LR) and the item-response-theory-likelihood-ratio test (IRT-LRT), capable of detecting both unidirectional and non-unidirectional DIF, to the CAT environment in which pretest items are assumed to be seeded in CATs but not used for trait estimation. The proposed adaptation methods were evaluated with simulated data under different sample size ratios and impact conditions in terms of Type I error, power, and specificity in identifying the form of DIF. The adapted LR and IRT-LRT procedures are more powerful than the CAT version of SIBTEST for non-unidirectional DIF detection. The good Type I error control provided by IRT-LRT under extremely unequal sample sizes and large impact is encouraging. Implications of these and other findings are discussed. all rights reserved)},
	keywords = {computerized adaptive testing, educational testing, item response theory likelihood ratio test, logistic regression, trait estimation, unidirectional \& non-unidirectional differential item functioning},
	isbn = {0022-0655 (Print)},
	author = {Lei, P-W. and Chen, S-Y. and Yu, L.}
}
@article {72,
	title = {Controlling item exposure and test overlap in computerized adaptive testing},
	journal = {Applied Psychological Measurement},
	volume = {29},
	number = {3},
	year = {2005},
	pages = {204-217},
	abstract = {This article proposes an item exposure control method, which is the extension of the Sympson and Hetter procedure and can provide item exposure control at both the item and test levels. Item exposure rate and test overlap rate are two indices commonly used to track item exposure in computerized adaptive tests. By considering both indices, item exposure can be monitored at both the item and test levels. To control the item exposure rate and test overlap rate simultaneously, the modified procedure attempted to control not only the maximum value but also the variance of item exposure rates. Results indicated that the item exposure rate and test overlap rate could be controlled simultaneously by implementing the modified procedure. Item exposure control was improved and precision of trait estimation decreased when a prespecified maximum test overlap rate was stringent. (PsycINFO Database Record (c) 2005 APA ) (journal abstract)},
	keywords = {Adaptive Testing, Computer Assisted Testing, Item Content (Test) computerized adaptive testing},
	author = {Chen, S-Y. and Lei, P-W.}
}
@article {69,
	title = {Effects of practical constraints on item selection rules at the early stages of computerized adaptive testing},
	journal = {Journal of Educational Measurement},
	volume = {41},
	number = {2},
	year = {2004},
	pages = {149-174},
	publisher = {Blackwell Publishing: United Kingdom},
	abstract = {The purpose of this study was to compare the effects of four item selection rules--(1) Fisher information (F), (2) Fisher information with a posterior distribution (FP), (3) Kullback-Leibler information with a posterior distribution (KP), and (4) completely randomized item selection (RN)--with respect to the precision of trait estimation and the extent of item usage at the early stages of computerized adaptive testing. The comparison of the four item selection rules was carried out under three conditions: (1) using only the item information function as the item selection criterion; (2) using both the item information function and content balancing; and (3) using the item information function, content balancing, and item exposure control. When test length was less than 10 items, FP and KP tended to outperform F at extreme trait levels in Condition 1. However, in more realistic settings, it could not be concluded that FP and KP outperformed F, especially when item exposure control was imposed. When test length was greater than 10 items, the three nonrandom item selection procedures performed similarly no matter what the condition was, while F had slightly higher item usage. (PsycINFO Database Record (c) 2007 APA, all rights reserved)},
	keywords = {computerized adaptive testing, item selection rules, practical constraints},
	isbn = {0022-0655 (Print)},
	author = {Chen, S-Y. and Ankenmann, R. D.}
}
@conference {883,
	title = {Predicting item exposure parameters in computerized adaptive testing},
	booktitle = {Paper presented at the annual meeting of the American Educational Research Association},
	year = {2003},
	note = {{PDF file, 239 KB}},
	address = {Chicago IL},
	author = {Chen, S-Y. and Doong, H.}
}
@article {68,
	title = {The relationship between item exposure and test overlap in computerized adaptive testing},
	journal = {Journal of Educational Measurement},
	volume = {40},
	number = {2},
	year = {2003},
	pages = {129-145},
	abstract = {The purpose of this article is to present an analytical derivation for the mathematical form of an average between-test overlap index as a function of the item exposure index, for fixed-length computerized adaptive tests (CATs). This algebraic relationship is used to investigate the simultaneous control of item exposure at both the item and test levels. The results indicate that, in fixed-length CATs, control of the average between-test overlap is achieved via the mean and variance of the item exposure rates of the items that constitute the CAT item pool. The mean of the item exposure rates is easily manipulated. Control over the variance of the item exposure rates can be achieved via the maximum item exposure rate (r-sub(max)). Therefore, item exposure control methods which implement a specification of r-sub(max) (e.g., J. B. Sympson and R. D. Hetter, 1985) provide the most direct control at both the item and test levels. (PsycINFO Database Record (c) 2005 APA )},
	keywords = {(Statistical), Adaptive Testing, Computer Assisted Testing, Human Computer, Interaction computerized adaptive testing, Item Analysis, Item Analysis (Test), Test Items},
	author = {Chen, S-Y. and Ankemann, R. D. and Spray, J. A.}
}
@conference {881,
	title = {A new approach to simulation studies in computerized adaptive testing},
	booktitle = {Paper presented at the annual meeting of the American Educational Research Association},
	year = {2001},
	note = {{PDF file, 251 KB}},
	address = {Seattle WA},
	author = {Chen, S-Y.}
}
@article {70,
	title = {A comparison of item selection rules at the early stages of computerized adaptive testing},
	journal = {Applied Psychological Measurement},
	volume = {24},
	number = {3},
	year = {2000},
	pages = {241-255},
	abstract = {The effects of 5 item selection rules--Fisher information (FI), Fisher interval information (FII), Fisher information with a posterior distribution (FIP), Kullback-Leibler information (KL), and Kullback-Leibler information with a posterior distribution (KLP)--were compared with respect to the efficiency and precision of trait (θ) estimation at the early stages of computerized adaptive testing (CAT). FII, FIP, KL, and KLP performed marginally better than FI at the early stages of CAT for θ=-3 and -2. For tests longer than 10 items, there appeared to be no precision advantage for any of the selection rules. (PsycINFO Database Record (c) 2005 APA ) (journal abstract)},
	keywords = {Adaptive Testing, Computer Assisted Testing, Item Analysis (Test), Statistical Estimation computerized adaptive testing},
	author = {Chen, S-Y. and Ankenmann, R. D. and Chang, Hua-Hua}
}
@booklet {1349,
	title = {Exploring the relationship between item exposure rate and test overlap rate in computerized adaptive testing (ACT Research Report series 99-5)},
	year = {1999},
	note = {(also National Council on Measurement in Education paper, 1999).},
	address = {Iowa City IA: ACT, Inc},
	author = {Chen, S-Y. and Ankenmann, R. D. and Spray, J. A.}
}
