The effective evaluation of correctional programs is critically important. However, research in corrections rarely allows for the randomization of offenders to conditions of the study. This limitation compromises internal validity, and thus, causal conclusions can rarely be drawn. Increasingly, researchers are employing propensity score matching…

Although the primary responsibility rests with the authors of articles reporting nonsignificant results to demonstrate the worth of the results by discussing the power of the tests, consumers should be prepared to conduct their own power analyses. This article demonstrates the use of power analysis for the interpretation of nonsignificant…

A Monte Carlo technique was used to investigate the effect of the differences in covariate means among treatment groups on the significance level and the power of the F-test of the analysis of covariance. (Author/GDC)

An explanation of the misuse of statistical significance testing and the true meaning of "significance" is offered. Literature about the criticism of current practices of researchers and publications is reviewed in the context of tests of significance. The problem under consideration occurs when researchers attempt to do more than just establish…

Researchers increasingly recognize that significance tests are limited in their ability to inform scientific practice. Common errors in interpreting significance tests and three strategies for augmenting the interpretation of significance test results are illustrated. The first strategy for augmenting the interpretation of significance tests…

This review of the procedures involved in using path analysis provides guidelines for more effective future utilization of recursive path analysis in the field of family studies. (Author)

Kaufman and Sweet's article on the regression analysis of unbalanced factorial designs (EJ 111 767) is reviewed. A number of errors are noted, and relevant literature is cited. (GDC)

Research hypotheses versus statistical hypotheses, null hypotheses and alternative hypotheses, and statistical significance versus practical significance are described and illustrated. (CP)

Hintzman's 1980 attack on certain analyses in memory research is based on doubtful presumptions, namely, that contingency tables are inherently suspect as evidence for or against scientific conclusions and that pressing this logical argument is in some way an acceptable substitute for empirically examining the conclusions in question. (Author)

Although it makes a great deal of sense to attempt to design reading research so as to be able to generalize beyond the particular reading passages used in an experiment, the suggestion that tests of statistical significance are a necessary part of making valid generalizations is nonsense. (HOD)

A test of statistical significance is a procedure for determining how likely a result is assuming a null hypothesis to be true with randomization and a sample of size n (the given size in the study). Randomization, which refers to random sampling and random assignment, is important because it ensures the independence of observations, but it does…

Exploratory research with large numbers of variables and even larger numbers of relationships is likely to result in frequent Type II errors; that is falsely accepting an incorrect null hypotheses. There are three ways of reducing Type II errors: (1) choosing a lower significance level, which then increases the probability of Type I error; (2)…

Knowledge of the magnitude of effect(s) of an experimental study in science education should be of utmost concern to researchers in the field, but is often not reported. This document describes the concept of "explained variance" in analysis of variance designs and then explains how it can be calculated and reported. Reporting the magnitude of…

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…

Reviews the role of statistical significance testing, and argues that dominance of such testing is dysfunctional because significance tests do not provide the information that many researchers assume they do. Possible reasons for the persistence of statistical significance testing are discussed briefly, and ways to moderate negative effects are…