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)

Two algorithms that automatically select subsets of variables (PACE algorithm) and reference variables (Fabin estimators), respectively, used for the noniterative estimators are presented. The PACE algorithm is based on a nonsymmetric matrix sweep operator. A Monte Carlo experiment compares the relative performance of these estimators and others.…

A mathematical formula is introduced for the effect of integrating data. A method is then derived to eliminate the effect from correlations of variables, including mean composites, thus allowing for a clustering algorithm that requires allocation of variables according to the magnitude of their correlations. Examples illustrate the procedure. (SLD)

Demonstrated is the use of BASIC computer programs to simulate a binomial experiment and test a simple statistical hypothesis. The theoretical results are reached with the third programing attempt. All results, as well as computer programs, are included. (JJK)

The test proposed by Brien, Venables, and Mayo (1984), endorsed by Silver and Dunlap, and supported by computer software that they developed is not a proper test for multivariate independence. A revised appraisal is suggested for the Silver and Dunlap results. (SLD)

A Monte Carlo study was conducted using simulated dichotomous data to determine the effects of guessing on Rasch item fit statistics and the Logit Residual Index. Results indicate that no significant differences were found between the mean Rasch item fit statistics for each distribution type as the probability of guessing the correct answer…

The closed-interval signed area (CSA) and closed-interval unsigned area (CUA) statistics were studied by Monte Carlo simulation to detect differential item functioning (DIF) when the reference and focal groups had different parameter distributions. Different behaviors of the CSA and CUA as functions of the parameters are discussed. (SLD)

Psychometric issues pertinent to the application of an item-response-theory-based person-fit (response aberrancy) detection statistic in the personality measurement domain were explored using Monte Carlo methods. Recommendations are made about proper implementation of person-fit statistics in personality measurement. (SLD)

Evaluated the relative accuracy of the weighted likelihood estimate (WLE) of T. Warm (1989) compared to the maximum likelihood estimate (MLE), expected a posteriori estimate, and maximum a posteriori estimate. Results of the Monte Carlo study, which show the relative advantages of each approach, suggest that the test termination rule has more…

Examined the performance of a recently available full information maximum likelihood (FIML) estimator in a multiple regression model with missing data using Monte Carlo simulation and considering the effects of four independent variables. Results indicate that FIML estimation was superior to that of three ad hoc techniques, with less bias and less…

This article proposes a new approach to the statistical analysis of pairwisepresent covariance structure data. The estimator is based on maximizing the complete data likelihood function, and the associated test statistic and standard errors are corrected for misspecification using Satorra-Bentler corrections. A Monte Carlo study was conducted to…

A new methodology is proposed for the simultaneous reduction of units, variables, and occasions of a three-mode data set. Units are partitioned into a reduced number of classes, while, simultaneously, components for variables and occasions accounting for the largest common information for the classification are identified. The model is a…

Time-window sequential analyses test whether a target behavior occurs within a temporal window (e.g., within 2 seconds) after an antecedent behavior more than is expected by chance. This type of question is common when we need to know how one person or event may immediately affect another event or person in the natural environment. Theoretically,…

In separate studies, observers viewed upright biological motion, inverted biological motion, or arbitrary motion created from systematically randomizing the positions of point-light dots. Results showed that observers (a) could learn to detect the presence of arbitrary motion, (b) could not learn to discriminate the coherence of arbitrary motion,…