Traditionally, confirmatory factor analytic models are tested against a null model of total independence. Using randomly generated factors in a matrix of 46 aptitude tests, this approach is shown to be unlikely to reject even random factors. An alternative null model, based on a single general factor, is suggested. In addition, an index of model…

The validity of the equipercentile hypothesis of the Title I Evaluation and Reporting System norm-referenced evaluation model was examined using 3,224 seventh- and ninth-grade students. Findings from confidence interval procedures contradicted the equipercentile hypothesis. There was a pattern of large gains for students not receiving any special…

In a multiple (or multivariate) regression model where the predictors are subject to errors of measurement with a known variance-covariance structure, two-sample hypotheses are formulated for (i) equality of regressions on true scores and (ii) equality of residual variance (or covariance matrices) after regression on true scores. The hypotheses…

An empirical study was conducted in order to obtain treatment effect estimates with the Special Regression model for groups in which there was no treatment. General mathematics test scores were obtained from 730 ninth graders in city schools somewhat similar to Title I schools, but in which no special treatments were given. Hypothetical…

Describes changes in scientific research methods that have been brought about by the use of computers. Presents an example of the falling of a body in a fluid to show students how computers can be used to experiment with mathematical models and to automate experiments. Contains 11 references. (Author/WRM)