Consider the nonparametric regression model Y = m(X)+ [tau](X)[epsilon], where X and [epsilon] are independent random variables, [epsilon] has a median of zero and variance [sigma][squared], [tau] is some unknown function used to model heteroscedasticity, and m(X) is an unknown function reflecting some conditional measure of location associated…

The first eigenvalue of a correlation matrix indicates the maximum amount of the variance of the variables which can be accounted for with a linear model by a single underlying factor. The first eigenvalue measures the primary cluster in the matrix, its number of variables and average correlation. (Author/RL)

A method based on three variance computations and some minor arithmetic is presented as an alternative to criterion-scale regression for the computation of a repeated measures-randomized blocks analysis of variance (RMBANOVA). The use of margin sum and cell variances can simplify the analysis of data for RMBANOVA. (SLD)

The form of the Johnson-Neyman region of significance is shown to be determined by the statistic for testing the null hypothesis that the population within-group regressions are parallel. Results are obtained for both simultaneous and nonsimultaneous regions of significance. (Author)

New methods of analysis--equations and graphs for iso-r(sup 2) contours--were introduced and used to illustrate location effects for pooled data sets. The "r(sup 2)" is the coefficient of determination. Results are used to highlight imprecise statements in the literature about the behavior of the correlation coefficient for pooled data…

A linear regression function is developed for use in a classification procedure. The procedure is applied to faculty merit review data, resulting in an interpretable regression function and within-sample classifications as good as a four-funtion discriminant analysis. (Author/BW)

If heterogeneous regression slopes are present in analysis of covariance (ANCOVA), the likelihood of committing a Type I error is greater than what had been prespecified. The power of the ANCOVA test of hypothesis for all possible differences of treatment effects is not maximized. (Author/RL)

The development of a nonparametric K-sample test for equality of slopes using Puri's generalized L statistic is presented. The test is recommended when the assumptions underlying the parametric model are violated. This procedure replaces original data with either ranks (for data with heavy tails) or normal scores (for data with light tails).…

An analytic procedure is presented for testing the homogeneity of unstandardized regression weight vectors when the vectors are correlated. The basic design involves repeated measurements on a dependent variable and a set of independent variables. The method is illustrated with a study of perceived leader behavior. (Author/BW)

A method requiring minimal computational effort is presented for transforming ordered residuals for purposes of testing the correctness of a regression model. The method maintains the same logical ordering in the transformed residuals as that of the original residuals and is suitable for either correlated or uncorrelated data. (Author/BS)

An integrated study of Shine's actualized and pure single-subject behavior functions can produce more information than studying only one function. After summarizing the mathematics behind Shine's viewpoint, an ordinary regression analysis approach to the actualized behavior function is integrated with a time-series analysis approach to the pure…

Based on data from 411 Filipino secondary school students, the hypothesis was tested that press for achievement from parents, peers, and teachers mediates the relationship between school grades from one year to the next. No support was found for this contention after linear and curvilinear regression models were examined. (Author/LMO)

The present study compared six methods, two of which utilize the content structure of items, to estimate total-test scores using 450 students and 60 items of the 110-item Stanford Mental Arithmetic Test. Three methods yielded fairly good estimates of the total-test score. (Author/RL)

The concept of change is related to suppressor variable conditions in a least square regression model. The domain of conditions necessary for a weighted change score composite to emerge as an underlying construct is mapped and the information loss through arbitrary assignment of weights to a change composite is explored. (Author/BW)

The present study compares the robustness of two different one way fixed-effects analysis of covariance (ANCOVA) models to investigate whether the model which uses a test statistic incorporating estimates of separate unequal regression slopes is more robust than the conventional model which assumes the slopes are equal. (Author/BW)