When item response data do not satisfy the unidimensionality assumption, multidimensional item response theory (MIRT) should be used to model the item-examinee interaction. This article presents and discusses MIRT analyses designed to give better insight into what individual items are measuring. (SLD)

Three heuristic methods of assessing the dimensionality of binary item pools were evaluated in a Monte Carlo investigation. The indices were based on (1) the local independence of unidimensional tests; (2) patterns of second-factor loadings derived from simplex theory; and (3) the shape of the curve of successive eigenvalues. (SLD)

A testlet is an integrated group of test items presented as a unit. The concept of testlet differential item functioning (testlet DIF) is defined, and a statistical method is presented to detect testlet DIF. Data from a testlet-based experimental version of the Scholastic Aptitude Test illustrate the methodology. (SLD)

An approximation for the bias function of the maximum likelihood estimate of the latent trait or ability is developed for the general case where item responses are discrete, which includes the dichotomous response level, the graded response level, and the nominal response level. (SLD)

The tendency of some respondents to omit items more often when they feel they have a less positive evaluation to make and less frequently when the evaluation is more positive is discussed. Five examples illustrate this form of nonresponse bias. Recommendations to overcome nonresponse bias are offered. (SLD)

Investigates whether the vocabulary of written comprehension questions is an independent factor in determining students' reading comprehension performance. Finds that academic vocabulary in comprehension questions significantly decreased question-answering performance. Computes simple, multiple, and semipartial correlations between vocabulary…

Presents a job aid for determining test-item format called TIFAID (Test Item Format Job Aid), based on adequately constructed instructional objectives. The four sections of the job aid are described: (1) a task classification system; (2) task-related questions; (3) a flowchart; and (4) a tips and techniques guide. (Contains four references.) (LRW)

Examined were the responses of park visitors to the New Environmental Paradigm scale. Research methods, and results including reliabilities and factor analysis of the scales on the survey are discussed. (CW)

A network-flow model is formulated for constructing parallel tests based on classical test theory while using test reliability as the criterion. Practitioners can specify a test-difficulty distribution for values of item difficulties as well as test-composition requirements. An empirical study illustrates the reliability of generated tests. (SLD)

The phenomenon of simultaneous differential item functioning (DIF) amplification and cancellation and the role of the SIBTEST approach in detecting DIF are investigated with a variety of simulated test data. The effectiveness of SIBTEST is supported, and the implications of DIF amplification and cancellation are discussed. (SLD)

A method is presented for incorporating a large number of constraints on adaptive item selection in the construction of computerized adaptive tests. The method, which emulates practices of expert test specialists, is illustrated for verbal and quantitative measures. Its foundation is application of a weighted deviations model and algorithm. (SLD)

Three measures of differential item functioning for the dichotomous response model are extended to include Samejima's graded response model. Two are based on area differences between item true score functions, and one is a chi-square statistic for comparing differences in item parameters. (SLD)

Three potential causes of scale shrinkage (measurement error, restriction of range, and multidimensionality) in item response theory vertical equating are discussed, and a more comprehensive model-based approach to establishing vertical scales is described. Test data from the National Assessment of Educational Progress are used to illustrate the…

Administered a questionnaire focusing on examinees' computer familiarity to 90,000 Test of English as a Foreign Language test takers. A group of 1,200 low-computer-familiar and high-computer-familiar examinees' worked through a computer tutorial and a set of TOEFL test items. Concludes that no evidence exists of an adverse relationship between…

Describes how a researcher used student cooperative-learning teams to contribute test items. Discusses the questions generated by students and concludes that teachers have the flexibility to encourage students to generate and solve their own problems. Also concludes that students have the opportunity to be creative and formulate and pose questions…