A common question asked by researchers using regression models is, What sample size is needed for my study? While there are formulae to estimate sample sizes, their assumptions are often not met in the collected data. A more realistic approach to sample size determination requires more information such as the model of interest, strength of the…

Grouping is a statistical procedure through which members of the same group are considered as a single unit of observation. There are various ways to assign group membership and various ways to assign values of variables to groups. There are methodological problems associated with grouping in general and with particular methods of grouping. This…

Thirty-four papers on educational statistics which were presented at the 1971 AERA Conference are summarized. Six major interest areas are covered: (a) general information; (b) non-parametric methods; (c) errors of measurement and correlation techniques; (d) regression theory; (e) univariate and multivariate analysis; (f) factor analysis. (MS)

Using a Monte Carlo approach, comparison was made between traditional procedures and a multiple linear regression approach to test for differences between values of r sub 1 and r sub 2 when sample data were dependent and independent. For independent sample data, results from a z-test were compared to results from using multiple linear regression.…

The accuracy and variability of 4 cross-validation procedures and 18 formulas were compared concerning their ability to estimate the population multiple correlation and the validity of the sample regression equation in the population. The investigation included two types of regression, multiple and stepwise; three sample sizes, N = 30, 60, 120;…

To determine the factors that influence interpretation of a research study description, 8 descriptions of research studies were interpreted by 320 undergraduate students in psychology, mathematics, and economics statistics and research methods classes at the University of Victoria (British Columbia, Canada), Millersville University (Pennsylvania),…

A broad spectrum of methodologies pertinent to studies of schooling effects are reviewed. Methodological issues and problems are addressed according to a three-dimensional conceptual framework: (1) indicators of schooling effects; (2) study approaches; and (3) units of analysis. Problems and uses of status attainment and difference scores as…