Two objectives guided the present study: (1) to provide a suitable test for the hypothesis rho=0, and (2) to establish a means by which general users of R can set confidence intervals on rho. The first objective was approached by testing several possible solutions similar to the procedure followed by Forsyth. The second objective was pursued via a…

The logic and procedures underlying a disturbance term regression test of logical consistency for structural models are reviewed for recursive and nonrecursive designs. It is shown that in a simple three-variable, complete mediational case the test procedure is mathematically equivalent to a part correlation. (Author/LMO)

New tests for comparing the strength of association between a variable and each of two potential predictor variables are proposed and compared to an existing test in a simulation study. Recommendations for use are made. (Author/JKS)

A computer program randomly sampled ordered pairs of scores from known populations that departed from bivariate normal form and calculated correlation coefficients from sample values. Hypotheses were tested (1) that population correlations are zero using the t statistic; and (2) that population correlations have non-zero values using the r to z…

Multiple-hypothesis testing in the context of a correlation matrix is used to compare the statistical power of the original Bonferroni with six modified Bonferroni procedures that control the overall Type I error rate. Three definitions of statistical power are considered: (1) the ability to detect at least one true relationship; (2) the ability…

This article proposes a method for testing equality of variances which exploits Pitman's idea and the computational power of simulations. Several advantages to this method are illustrated. A Monte Carlo study for several combinations of sample sizes and number of variables is presented. (Author/LMO)

A study was conducted to determine why the theoretical relationship between dogmatism and conformity had not been verified in correlation studies. The study was designed to study the effect of differing statistical treatments on the coefficient of correlation. Data generated in an experimental framework included conformity scores and dogmatism…

The t ratio used in testing the difference between two independent regression coefficients is generalized to the multivariate case of testing the difference between two vectors of regression coefficients. This is particularly useful in determining which of two variables best predicts a number of criterion variables. (Author/JKS)

Intraclass correlation reliability estimates are based on the assumption that the various measures are equivalent. Joreskog's (1970) general model for the analysis of covariance structures can be used to test the validity of this assumption. (For related document, see TM 002 301.) (Author)

We are concerned with the hypothesis that two variables have a perfect disattenuated correlation, hence measure the same trait except for errors of measurement. This hypothesis is equivalent to saying, within the adopted model, that true scores of two psychological tests satisfy a linear relation. A statistical test of this hypothesis is derived…

Two easily computed test statistics are proposed for testing the equality of two correlated proportions when some observations are missing on both responses. The performance of these tests in terms of size and power is compared with other tests by means of Monte Carlo simulations. (Author/BS)

This paper discusses distribution theory and power computations for four common "tests of combined significance." These tests are calculated using one-sided sample probabilities or p values from independent studies (or hypothesis tests), and provide an overall significance level for the series of results. Noncentral asymptotic sampling…

The tests for zero partial association in a multiple contingency table have gained new importance with the introduction of graphical models. It is shown how these may be performed as exact conditional tests, using as test criteria either the ordinary likelihood ratio, the standard x squared statistic, or any other appropriate statistics. A…

This study examined the effect of type of correlation matrix on the robustness of LISREL maximum likelihood and unweighted least squares structural parameter estimates for models with categorical manifest variables. Two types of correlation matrices were analyzed; one containing Pearson product-moment correlations and one containing tetrachoric,…

The purpose of this study was to empirically determine the effects of quantified violations of the underlying assumptions of parametric statistical tests commonly used in educational research, namely the correlation coefficient (r) and the t test. The effects of heterogeneity of variance, nonnormality, and nonlinear transformations of scales were…