TY - JOUR T1 - Comparison of two Bayesian methods to detect mode effects between paper-based and computerized adaptive assessments: a preliminary Monte Carlo study. JF - BMC Med Res Methodol Y1 - 2012 A1 - Riley, Barth B A1 - Carle, Adam C KW - Bayes Theorem KW - Data Interpretation, Statistical KW - Humans KW - Mathematical Computing KW - Monte Carlo Method KW - Outcome Assessment (Health Care) AB -

BACKGROUND: Computerized adaptive testing (CAT) is being applied to health outcome measures developed as paper-and-pencil (P&P) instruments. Differences in how respondents answer items administered by CAT vs. P&P can increase error in CAT-estimated measures if not identified and corrected.

METHOD: Two methods for detecting item-level mode effects are proposed using Bayesian estimation of posterior distributions of item parameters: (1) a modified robust Z (RZ) test, and (2) 95% credible intervals (CrI) for the CAT-P&P difference in item difficulty. A simulation study was conducted under the following conditions: (1) data-generating model (one- vs. two-parameter IRT model); (2) moderate vs. large DIF sizes; (3) percentage of DIF items (10% vs. 30%), and (4) mean difference in θ estimates across modes of 0 vs. 1 logits. This resulted in a total of 16 conditions with 10 generated datasets per condition.

RESULTS: Both methods evidenced good to excellent false positive control, with RZ providing better control of false positives and with slightly higher power for CrI, irrespective of measurement model. False positives increased when items were very easy to endorse and when there with mode differences in mean trait level. True positives were predicted by CAT item usage, absolute item difficulty and item discrimination. RZ outperformed CrI, due to better control of false positive DIF.

CONCLUSIONS: Whereas false positives were well controlled, particularly for RZ, power to detect DIF was suboptimal. Research is needed to examine the robustness of these methods under varying prior assumptions concerning the distribution of item and person parameters and when data fail to conform to prior assumptions. False identification of DIF when items were very easy to endorse is a problem warranting additional investigation.

VL - 12 ER - TY - JOUR T1 - The maximum priority index method for severely constrained item selection in computerized adaptive testing JF - British Journal of Mathematical and Statistical Psychology Y1 - 2009 A1 - Cheng, Y A1 - Chang, Hua-Hua KW - Aptitude Tests/*statistics & numerical data KW - Diagnosis, Computer-Assisted/*statistics & numerical data KW - Educational Measurement/*statistics & numerical data KW - Humans KW - Mathematical Computing KW - Models, Statistical KW - Personality Tests/*statistics & numerical data KW - Psychometrics/*statistics & numerical data KW - Reproducibility of Results KW - Software AB - This paper introduces a new heuristic approach, the maximum priority index (MPI) method, for severely constrained item selection in computerized adaptive testing. Our simulation study shows that it is able to accommodate various non-statistical constraints simultaneously, such as content balancing, exposure control, answer key balancing, and so on. Compared with the weighted deviation modelling method, it leads to fewer constraint violations and better exposure control while maintaining the same level of measurement precision. VL - 62 SN - 0007-1102 (Print)0007-1102 (Linking) N1 - Cheng, YingChang, Hua-HuaResearch Support, Non-U.S. Gov'tEnglandThe British journal of mathematical and statistical psychologyBr J Math Stat Psychol. 2009 May;62(Pt 2):369-83. Epub 2008 Jun 2. ER - TY - JOUR T1 - Rotating item banks versus restriction of maximum exposure rates in computerized adaptive testing JF - Spanish Journal of Psychology Y1 - 2008 A1 - Barrada, J A1 - Olea, J. A1 - Abad, F. J. KW - *Character KW - *Databases KW - *Software Design KW - Aptitude Tests/*statistics & numerical data KW - Bias (Epidemiology) KW - Computing Methodologies KW - Diagnosis, Computer-Assisted/*statistics & numerical data KW - Educational Measurement/*statistics & numerical data KW - Humans KW - Mathematical Computing KW - Psychometrics/statistics & numerical data AB -

If examinees were to know, beforehand, part of the content of a computerized adaptive test, their estimated trait levels would then have a marked positive bias. One of the strategies to avoid this consists of dividing a large item bank into several sub-banks and rotating the sub-bank employed (Ariel, Veldkamp & van der Linden, 2004). This strategy permits substantial improvements in exposure control at little cost to measurement accuracy, However, we do not know whether this option provides better results than using the master bank with greater restriction in the maximum exposure rates (Sympson & Hetter, 1985). In order to investigate this issue, we worked with several simulated banks of 2100 items, comparing them, for RMSE and overlap rate, with the same banks divided in two, three... up to seven sub-banks. By means of extensive manipulation of the maximum exposure rate in each bank, we found that the option of rotating banks slightly outperformed the option of restricting maximum exposure rate of the master bank by means of the Sympson-Hetter method.

VL - 11 SN - 1138-7416 N1 - Barrada, Juan RamonOlea, JulioAbad, Francisco JoseResearch Support, Non-U.S. Gov'tSpainThe Spanish journal of psychologySpan J Psychol. 2008 Nov;11(2):618-25. ER - TY - JOUR T1 - Item response theory and health outcomes measurement in the 21st century JF - Medical Care Y1 - 2000 A1 - Hays, R. D. A1 - Morales, L. S. A1 - Reise, S. P. KW - *Models, Statistical KW - Activities of Daily Living KW - Data Interpretation, Statistical KW - Health Services Research/*methods KW - Health Surveys KW - Human KW - Mathematical Computing KW - Outcome Assessment (Health Care)/*methods KW - Research Design KW - Support, Non-U.S. Gov't KW - Support, U.S. Gov't, P.H.S. KW - United States AB - Item response theory (IRT) has a number of potential advantages over classical test theory in assessing self-reported health outcomes. IRT models yield invariant item and latent trait estimates (within a linear transformation), standard errors conditional on trait level, and trait estimates anchored to item content. IRT also facilitates evaluation of differential item functioning, inclusion of items with different response formats in the same scale, and assessment of person fit and is ideally suited for implementing computer adaptive testing. Finally, IRT methods can be helpful in developing better health outcome measures and in assessing change over time. These issues are reviewed, along with a discussion of some of the methodological and practical challenges in applying IRT methods. VL - 38 N1 - 204349670025-7079Journal Article ER -