Varied the number of items and categories per item to explore the effects on estimation of item parameters in the nominal response model. Simulation results show that increasing the number of items had little effect on item parameter recovery, but increasing the number of categories increased the error variance of the parameter estimates. (SLD)

Evaluated two strategies for scoring context-dependent test items: ignoring the depending and scoring dichotomously or modeling the dependence through polytomous scoring. Results for data from 38,965 examinees taking a professional examination show that dichotomous scoring may overestimate test information, but polytomous scoring may underestimate…

Compared the properties of five methods of item exposure control in the context of estimating examinees' abilities in a computerized adaptive testing situation. Findings show advantages to the Stocking and Lewis conditional multinomial procedure (M. Stocking and C. Lewis, 1995) and, to a lesser degree, the Davy and Parshall method (T. Davey and C.…

Studied calibration designs that maximize the determinants of Fisher's information matrix on the item parameters for sets of polytomously scored items. Analyzed these items using a number of item response theory models. Results show that for the data and models used, a D-optimal calibration design for an answer or set of answers can reduce the…

Provides a tutorial on differential item functioning (DIF) and reviews DIFPACK, a new software package that is specifically designed to test for the presence of DIF. DIFPACK allows the user to test for standard unidirectional DIF, DIF in dichotomous items, DIF in polytomous items, and disordinal, or crossing, DIF. (SLD)

The book answers practical questions about item response theory (IRT) in four sections: (1) an introduction to the concepts; (2) IRT theories and principles; (3) fundamentals of IRT; and (4) applications of IRT models. The book is useful for anyone trying to learn about IRT and how to use it. (SLD)

The application of a class of Rasch models is discussed for situations in which test items are grouped into subsets and the common attributes of items within the subsets bring into question the usual assumption of conditional independence. Models are expressed as particular cases of the random coefficients multinomial logit model. (SLD)

Examined convergent and discriminant validity of selected Minnesota Multiphasic Personality Inventory--Adolescent (MMPI--A) content scales. A total of 62 adolescent psychiatric inpatients completed the inventory and a battery of self-report measures of constructs similar to the content scales. Findings support validity and potential utility of the…

For trinary partial credit items, the shape of the item information and item discrimination functions is examined in relation to the item parameters. Conditions under which these functions are unimodal and bimodal are discussed, and the locations and values of maxima are derived. Practical relevance of the results is discussed. (SLD)

Examined the frequency of use of various types of reliability coefficients for a sample of 696 tests in a directory published by the American Psychological Association. Coefficient alpha was the overwhelming favorite, and several measures treated almost universally in textbooks were rarely or never used. Identifies problems encountered in the…

Examined the effect of test purification in detecting differential item functioning (DIF) by means of polytomous extensions of the Raju area measures (N. Raju, 1990) and the Lord statistic (F. Lord, 1980). Simulation results suggest the necessity of using a two-stage equating purification process with the Raju exact measures and the Lord statistic…

This book is a compendium of recent item response theory (IRT) research that reviews 27 IRT models. The book contains a historical overview of IRT followed by six sections that deal with the application of a particular IRT model or set of models. (SLD)

Students prepared for classroom examinations by completing practice tests, with selected items from these practice tests repeated, in either the original or in a modified wording, on classroom examinations and a final examination. The availability of immediate self-corrective feedback on Study 1 practice tests (0, 3, or 6 practice tests) was…

Conditional probability and statistical independence can be better explained with contingency tables. In this note some special cases of 2 x 2 contingency tables are considered. In turn an interesting insight into statistical dependence as well as independence of events is obtained.

This study examines whether the Problem Based Economics curriculum developed by the Buck Institute for Education improves grade 12 students' content knowledge as measured by the Test of Economic Literacy, a test refined by the National Council on Economic Education (NCEE) over decades. Students' problem-solving skills in economics were also…