The authors describe a computer program which deals with sets of variables rather than with one variable at a time. (MM)

Methods for comparing the suitability of alternative models for covariance matrices are examined. A cross-validation procedure is suggested and its properties examined. A series of examples using longitudinal data are examined. (Author/JKS)

Compared six effect size (ES) measures commonly used by gerontological researchers as these measures relate to one another in both the analysis of variance and multiple regression models. Also discusses three other issues involving ES measures: the ES of a contrast; orthogonal and nonorthogonal designs; and partial ESs. (Author/JAC)

Assesses levels of depression presented by 76 male and 29 female alcoholics using Beck Depression Inventory and Hamilton Psychiatric Rating Scale for Depression. To estimate overall depression from the self-report and clinical instruments, Z scores for both measures were summed. Correlations were calculated between composite scores and alcoholics'…

Rationale and procedures for conducting process analysis in evaluation research are discussed. Two different procedures for estimating mediation are discussed, as well as procedures for examining whether a treatment exerts its effects, in part, by altering mediating process that produces outcome. Benefits of process analysis in evaluation research…

This article examines simple and multiple regression analysis as forecasting tools, and details the process by which multiple regression analysis may be used to increase the accuracy of the technology forecast. (CT)

The type I error rate in stepwise regression analysis deserves serious consideration by researchers. The problem-wide error rate is the probability of selecting any variable when all variables have population regression weights of zero. Appropriate significance tests are presented and a Monte Carlo experiment is described. (Author/CTM)

Three methods of handling disproportionate cell frequencies in two-way analysis of variance are examined. A Monte Carlo approach was used to study the method of expected frequencies and two multiple regression approaches to the problem as disproportionality increases. (Author/JKS)

A statistical analysis procedure is developed, based on the notion that many educational programs are dynamic interventions in natural growth processes, and is called value-added analysis. The theory of value-added analysis, and several applications are presented. (Author/JKS)

Computer programs for analysis of covariance use classical experimental, regression, or hierarchical methods of least squares. In a 3 X 3 factorial experiment with equal cell frequencies, three solutions yielded different sums of squares for main effects although correlation between variables was negligible and cell frequencies were equal.…

Three traditional methods of selection of variables to be included in a "best" regression equation are compared to a method designed to maximize weight validity. Implications for constructing regression equations for prediction are discussed, with consideration of the weight validity maximization method recommended in crucial situations.…

When sample sizes and/or X intervals are unequal, the analysis of variance computations for trend analysis become quite complicated. This article shows how multiple regression/correlation analysis may be applied in order to accomplish with great simplicity trend analysis under "irregular" conditions. (Author/RL)