BILOG is the defacto standard for dichotomous IRT model estimation. However, BILOG is a commercial product and limited in other ways. Hanson provides an open-source alternative, ICL, and this paper compares ICL to BILOG in terms of features and obtained item parameter estimates. In general, BILOG has more features, especially with respect to assessing model-data fit. One notable feature of ICL ...

This paper compares three methods of item calibration—concurrent calibration, separate calibration with linking, and fixed item parameter calibration—that are frequently used for linking item parameters to a base scale. Concurrent and separate calibrations were implemented using BILOG-MG. The Stocking and Lord (1983) characteristic curve method of parameter linking was used in conjunction with ...

Item response theory (IRT) has become one of the most popular scoring frameworks for measurement data. IRT models are used frequently in computerized adaptive testing, cognitively diagnostic assessment, and test equating. This article reviews two of the most popular software packages for IRT model estimation, BILOG-MG (Zimowski, Muraki, Mislevy, & Bock, 1996) and MULTILOG (Thissen, 1991), which...

Parameters of the two-parameter logistic model are generally estimated via the expectation-maximization algorithm, which improves initial values for all parameters iteratively until convergence is reached. Effects of initial values are rarely discussed in item response theory (IRT), but initial values were recently found to affect item parameters when estimating the latent distribution with ful...

Stable maximum likelihood estimation (MLE) of item parameters in 3PLM with a modest sample size remains a challenge. The current study presents a mixture-modeling approach to 3PLM based on which a feasible Expectation-Maximization-Maximization (EMM) MLE algorithm is proposed. The simulation study indicates that EMM is comparable to the Bayesian EM in terms of bias and RMSE. EMM also produces sm...

This study aims to describe the Physics test item parameters in Work and Energy students’ abilities using response theory approach (IRT) dichotomous scoring. research is quantitative descriptive. The subjects were 1175 high school class XI students West Java Banten provinces consisting of 450 male 725 female students. instrument used was as many 25 items multiple choices with Student data scori...

DOCUMENT RESUME TM 030 621 Hanson, Bradley A.; Beguin, Anton A. Separate versus Concurrent Estimation of IRT Item Parameters in the Common Item Equating Design. American Coll. Testing Program, Iowa City, IA. ACT-RR-99-8 1999-12-00 36p. ACT Research Report Series, PO Box 168, Iowa City, IA 52243-0168. Reports Evaluative (142) MF01/PCO2 Plus Postage. *Equated Scores; Estimation (Mathematics); *It...

Aiming at a unified view of the logics describing spatial structures, we introduce a general framework, BiLog, whose formulae characterise monoidal categories. As a first instance of the framework we consider bigraphs, which are emerging as a an interesting (meta-)model for spatial structures and distributed calculi. Since bigraphs are built orthogonally on two structures, a hierarchical place ...