The general purpose of this study was to examine the efficiency of the Precision Efficacy Analysis for Regression (PEAR) method for choosing appropriate sample sizes in regression studies used for precision. The PEAR method, which is based on the algebraic manipulation of an accepted cross-validity formula, essentially uses an effect size to…

In a Monte Carlo analysis of single-subject data, Type I and Type II error rates were compared for various statistical tests of the significance of treatment effects. Data for 5,000 subjects in each of 6 treatment effect size groups were computer simulated, and 2 types of treatment effects were simulated in the dependent variable during…

"The usefulness of a structural analysis of pretest items in designing an instructional system is illustrated by the application of this technique to 100 addition computation problems. (Author)

The details of EM algorithms for maximum likelihood factor analysis are presented for both the exploratory and confirmatory models. An example is presented to demonstrate potential problems in other approaches to maximum likelihood factor analysis. (Author/JKS)

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)

The advantages and assumptions of analysis of covariance (ANCOVA) and an alternative approach to ANCOVA which uses simultaneous and nonsimultaneous inference techniques are presented with an example of the latter's use. This approach is advocated for situations where it is suspected that dependent measures are a function of some initial aptitude…

Ridge regression offers advantages over ordinary least squares estimation when a validity shrinkage criterion is considered. Comparisons of cross-validated multiple correlations indicate that ridge estimation is superior when the predictors are multicollinear, the number of predictors is large relative to sample size, and the population multiple…

The accuracy of three procedures based upon past enrollment for 39 school districts was compared. Results show that accuracy of projection varies widely among school districts. Short-term projections were found to be more accurate than long-term. (Author/GK)

An empirical investigation of the statistical procedure entitled nonlinear principal components analysis was conducted on a known equation and on measurement data in order to demonstrate the procedure and examine its potential usefulness. This method was suggested by R. Gnanadesikan and based on an early paper of Karl Pearson. (Author/AL)

Graduate Record Examination and Miller Analogies Test scores were equated using linear transformation and regression methods. Standard deviations of regression equivalence scores were consistently smaller than those actually obtained in the sample, whereas standard deviations of linear equivalence scores were the same as those in the sample.…

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)

Analyses of data from a nutrition education program were compared for multiple regression analysis using individual subject data, multiple regression using classroom data, two-level random effects model (REM) with subjects clustered within classrooms, and two-level REM with subjects clustered within sites. Advantages of REM are discussed. (SLD)

Compares four closed-formula estimators (Burkett, Claudy, Rozeboom, Browne) and the omit-one method for estimating TRS, the true shrunken correlation (not to be confused with TR, the true multiple correlation). Recommendations are based on artificial populations with known TRS. (Author/SV)

Studied the efficiency and robustness of alternative estimators of regression coefficients for three-level data. A simulation study shows that, as expected, the hierarchical model analyses produced more efficient point estimates than did analyses that ignored the covariance structure in the data, even when the normality assumption was violated.…

Uses a unique data set crated by merging the Panel Study of Income Dynamics with school data from the Common Core of Data to examine the relationship between school expenditures and earnings. Finds that school expenditures are related to earnings, and also positively affect the returns to schooling. (Contains 23 references.) (Author/PKP)