Examples are given of problems that have solutions or discriminants'' similar to that of the quadratic formula; theorems pertaining to these problems are stated and proved. (DT)

One in a series of nine articles in a section entitled, Electronic Computer Program and Accounting Machine Procedures."

If the null hypothesis of a one-sample test of multivariate means is rejected, the dimension of the line joining the population centroid and the hypothesized centroid can be interpreted with a linear function, using a discriminant function and the correlation of each dependent variable with a discriminant score. (Author/BW)

Fisher's two-group discriminant function has been generalized in two different ways for the case of three or more groups, leading to confusion in the literature. The precise functional relation between the two functions is derived, and the interpretation of the two functions is discussed. An example is provided. (Author/CTM)

Recent trends in the analysis of categorical or nominal variables were discussed for univariate, multivariate, and psychometric problems. It was shown that several statistical procedures commonly used with these problems have analogues which can be applied to assessing categorical variables. (Author/CTM)

Methodological issues raised in a feasibility study to develop a psychological test to predict illicit drug use are described. A small set of items was found to be related to prior drug use. These items maintained their ability to discriminate users and non-users in a cross-validation study. (Author/JKS)

Predictive discriminant analysis and descriptive discriminant analysis are described, and the use of three popular statistical packages to obtain computational results for each type of discriminant analysis is reviewed. Results from two Biomedical Computer Program (BMDP), four Statistical Analysis System, and two Statistical Package for the Social…

Using the original validation sample for the Halstead-Reitan Neuropsychological Battery, a discriminant function analysis was performed to determine the best set of weights for the measures in its Impairment Index. Findings suggest that an empirically derived set of weights is probably no more useful than equal weighting commonly used. (SLD)

Three problems with stepwise research methods are explored. Computer packages may use incorrect degrees of freedom in stepwise computations. In addition, stepwise methods do not identify correctly the best variable set of a given size. A third problem is that stepwise methods tend to capitalize on sampling error. (SLD)

A methodology is proposed to optimize the training classification performance of any suboptimal model. The method, referred to as univariate optimal discriminant analysis (UniODA), is illustrated through application to a two-group logistic regression analysis with 12 empirical examples. Maximizing percentage accuracy in classification is…

A Statistical Analysis System (SAS) macro procedure for performing a jackknife analysis on structure coefficients in discriminant analysis is described together with issues and caveats about its use in multivariate methods. An example of use of the SAS macro is provided. (SLD)

Discusses information visualization techniques and introduces a visual term discrimination value analysis method using a document density space within a distance-angle-based visual information retrieval environment. Explains that applications of these methods facilitate more effective assignment of term weights to index terms within documents and…