Experimental psychology is witnessing an increase in research on individual differences, which requires the development of new tasks that can reliably assess variations among participants. To do this, cognitive researchers need statistical methods that many researchers have not learned during their training. The lack of expertise can pose…

Reliability is a property of test scores from individuals who have been sampled from a well-defined population. Reliability indices, such as coefficient and related formulas for internal consistency reliability (KR-20, Hoyt's reliability), yield lower bound reliability estimates when (a) subjects have been sampled from a single population and when…

It is sometimes desirable to obtain an estimated total-test score for an individual who was administered only a subset of the items in a total test. The present study compared six methods, two of which utilize the content structure of items, to estimate total-test scores using 450 students in grades 3-5 and 60 items of the ll0-item Stanford Mental…

A single conceptual and theoretical framework for sampling any configuration of data from one or more population matrices is presented, integrating past designs and discussing implications for more general designs. The theory is based upon a generalization of the generalized symmetric mean approach for single matrix samples. (Author/CTM)

Maximum likelihood factor analysis provides an effective method for estimation of factor matrices and a useful test statistic in the likelihood ratio for rejection of overly simple factor models. A reliability coefficient is proposed for analysis of factor solution. (Author/RK)

A general process for testing the feasibility of applying alternative mathematical or statistical models to the solution of a practical problem is presented and flowcharted. The system is used to compare five models for test equating: (1) anchor test equating using classical test theory; (2) anchor test equating using the one-parameter logistic…

Thirty-four papers on educational statistics which were presented at the 1971 AERA Conference are summarized. Six major interest areas are covered: (a) general information; (b) non-parametric methods; (c) errors of measurement and correlation techniques; (d) regression theory; (e) univariate and multivariate analysis; (f) factor analysis. (MS)