Diagnostic classification models (DCMs) are psychometric models that can be used to estimate the presence or absence of psychological traits, or proficiency on fine-grained skills. Critical to the use of any psychometric model in practice, including DCMs, is an evaluation of model fit. Traditionally, DCMs have been estimated with maximum…

An extensive review of the research literature and a study comparing over 36,000 survey responses with archival true scores indicated that one should expect a minimum of at least three percent random error for the least ambiguous of self-report measures. The Gulliver Effect occurs when a small proportion of error in a sizable subpopulation exerts…

Describes the temporal consistency of school classification observed in the Kentucky, and secondarily in the Charlotte-Mecklinberg (North Carolina), school-based performance award programs. Data from the Kentucky Department of Education show the extent to which temporal inconsistency could be due to measurement error. (SLD)

The uses and abuses of cut scores are examined. The article demonstrates (1) that cut scores always entail judgment; (2) that cut scores inherently result in misclassification; (3) that cut scores impose an artificial dichotomy on an essentially continuous distribution of knowledge, skill, or ability; and (4) that no true cut scores exist. (SLD)

A solution is offered to problems associated with the inequality in the manipulability of probabilities of classification errors of masters versus nonmasters, based on competency test results. Eschewing the typical arbitrary establishment of observed-score standards below 100 percent, the solution incorporates a self-correction of wrong answers.…

M. J. Kolen, B. A. Hanson, and R. L. Brennan (1992) presented a procedure for assessing the conditional standard error of measurement (CSEM) of scale scores using a strong true-score model. They also investigated the ways of using nonlinear transformation from number-correct raw score to scale score to equalize the conditional standard error along…

Three new indicators of psychometric quality for objectives-based statewide assessments are proposed. These measures provide indication of the stability of reported data on item and objectives mastery, the validity of assessment items for members of various cultural groups, and the convergent validity of prescribed objectives mastery scores. The…

Different item response theory (IRT) models may be employed for item calibration. Change of testing vendors, for example, may result in the adoption of a different model than that previously used with a testing program. To provide scale continuity and preserve cut score integrity, item parameter estimates from the new model must be linked to the…

Ways in which the Statistical Package for the Social Sciences (SPSS) can be used to perform some Rasch analyses are described in detail. It is shown how SPSS and a set of item calibrations can be used to estimate person abilities, standard errors of measurement, test characteristic curve, test information curve, classification consistency on a…