A new model for measuring misinformation is suggested. A modification of Wilcox's strong true-score model, to be used in certain situations, is indicated, since it solves the problem of correcting for guessing without assuming guessing is random. (Author/GK)

Two methods of constucting equal-interval scales for educational achievement are discussed: Thurstone's absolute scaling method and Item Response Theory. Alternative criteria for choosing a scale are contrasted. It is argued that clearer criteria are needed for judging the appropriateness and usefulness of alternative scaling procedures.…

A systematic method for compromise between absolute and relative examination standards is proposed. The passing score is assumed to be related to expected pass rate through a simple linear function. Results define a function relating the percentage of successful candidates given a specified passing score to the passing score. (Author/DWH)

A statistical method, W. F. Stout's statistical test of essential unidimensionality (1990), for exploring the lack of unidimensionality in test data was studied using Monte Carlo simulations. The statistical procedure is a hypothesis test of whether the essential dimensionality is one or exceeds one, regardless of the traditional dimensionality.…

A Monte Carlo study, which simulated 10,000 examinees' responses to four tests, investigated the effect of item stratification on parameter estimation in multiple matrix sampling of achievement data. Practical multiple matrix sampling is based on item stratification by item discrimination and a sampling plan with moderate number of subtests. (SLD)

Rasch model equatings of multilevel achievement test data before and after the deletion of misfitting persons were compared. Rasch equatings were also compared with an equating obtained using the equipercentile method. No basis could be found in the results for choosing between the two Rasch equatings. (Author/LMO)

The adequacy of equipercentile, linear, one-parameter (Rasch), and three-parameter logistic item-response theory procedures for equating 12 forms of five tests of general educational development were compared. Results indicated the equating method adequacy depends on a variety of factors such as test characteristics, equating design, and sample…

A procedure for obtaining maximum likelihood trait estimates from number-correct (NC) scores for the three-parameter logistic model is presented. It produces an NC score to trait estimate conversion table. Analyses in the estimated true score metric confirm the conclusions made in the trait metric. (Author/DWH)

Computer generated data are used to show that Slinde and Linn's criticism of the usefulness of the Rasch model for equating (EJ 189 585) may have been the result of an artifact produced by the manner in which the samples were chosen in their study. (CTM)

Longitudinal analyses of individual growth curves and the aggregation of individual curves to describe institutional growth were studied using achievement scores from students moving from grade one to grade eight and their ability scores for one year. Complete data for 529 individuals (reading) and 527 individuals (mathematics) were used. (SLD)

A method is presented for using a restricted latent class model--a binary skills model--to determine skills required by a set of test items. Results from the method's application to reading achievement data for about 63,000 fourth graders indicate that the model offers useful information on test structure and examinee ability. (TJH)

A procedure is presented for examining the influence of instruction on responses to test items by extending item response theory to incorporate variables illustrating different amounts of opportunity to learn. Data from the Second International Mathematics Study (grade 8 scores for about 7,000 students) illustrate the discussion. (SLD)