A test for multisample sphericity based on the efficient scores criterion is obtained as an alternative to the likelihood ratio test developed by Mendoza. (Author)

This article builds on an earlier discussion of the importance of the Type II error (beta) and power to the hypothesis testing process (CE 511 484), and illustrates the methods by which sample size calculations should be employed so as to improve the research process. (Author/CT)

Describes some of the situations in which a psychologist is likely to violate the assumption of independent errors. A Monte-Carlo study of the effects of this violation is then described. (Author/RC)

Evaluations involving nonrandom assignment to treatment or control groups are vulnerable to an accidental or intentional confounding of a selection effect with the treatment effect. Two techniques, discriminant analysis and base expectancy analysis, permit separate estimation of the selection and treatment effects in the final results. (Author/CTM)

Discusses the application of the Kolmogorov-Smirnov two-sample tests, as an alternative to the Chi-square test, for survey research problems in business education and includes a computer program written for the convenience of researchers. The two-sample test is recommended for differentiating independent distributions. (MF)

An investigation was conducted of the characteristics of two estimation procedures and corresponding test statistics used in the analysis of completely randomized factorial experiments when observations are lost at random. For one estimator, contrast coefficients for cell means did not involve the cell frequencies. For the other, contrast…

It is shown that using formulae for the estimation of sampling errors based on simple random sampling, when a design actually involves cluster sampling, can lead to serious underestimation of error. Jackknife and balanced repeated replication are recommended as techniques for dealing with this problem. (Author/CTM)

From a priori and post hoc data collection perspectives, this paper describes the interrelations among (1) power, alpha, effect size, and sample size for hypothesis testing; and (2) precision, confidence, and sample size for interval estimation. Implications for special education researchers working with convenient samples of fixed size are…

Too few researchers understand what statistical significance testing does and does not do, and consequently their results are misinterpreted. This Digest explains the concept of statistical significance testing and discusses the meaning of probabilities, the concept of statistical significance, arguments against significance testing,…

This study reexamines results reported by Angoff and Schrader regarding formula directions and rights directions for standardized tests. In that study, it was concluded that the two scoring directions were essentially equivalent. In this study, methodological concerns are discussed and additional data analyses undertaken. Among various…

This book, one of a series prepared in connection with the Behavioral and Social Sciences Survey (BASS) conducted between 1967 and 1969, deals with problems of statistics, mathematics, and computation as they related to the social sciences. Chapter 1 shows how these subjects help in their own ways for studying learning behavior with irregular…

In order to make policy decisions, educators must evaluate educational research proposals and projects. Findings immediately related to practice are often inadequate, omitting the theoretical establishment of principles by which we can explain and predict the phenomena of our world. These theoretical linkages to the practical world of…