A Monte Carlo study was done to determine the adequate sample size for quasi-experimental regression studies, which compare regression lines for two groups and estimate their point of intersection. Populations of 1,000 subjects in each of two groups were constructed (using random normal deviates) to yield equivalent regression lines of opposite…

This report describes a statistically designed experiment that was carried out in an operational setting to determine the contributions of different sources of variation to the unreliability of scoring. The experiment made novel use of partially balanced incomplete block designs that facilitated the unbiased estimation of certain main effects…

This report presents the results of a two-year project to design, pretest, and revise the Statistical Survey of Elementary Schools, which is intended to provide information on federally funded elementary education programs operating in local public school systems. The report also documents the activities and decisions that brought about these…

This report is about the problem of making transition or enrollment rate gains comparable. It is shown that measures based on the proportions themselves, i.e. the difference between proportions, the proportion ratio and the residual gain ratio do not make the gains comparable. Instead a non-linear transformation has to be done. Two such…

The effects of sample size, number of variables, and population value of the congruence coefficient on the sampling distribution of the congruence coefficient were examined. Sample data were generated on the basis of the common factor model, and principal axes factor analyses were performed. (Author/LMO)

The purpose of this study was to develop a single procedure for comparing population variances which could be used for distribution forms. Bootstrap methodology was used to estimate the variability of the sample variance statistic when the population distribution was normal, platykurtic and leptokurtic. The data for the study were generated and…

A normally distributed data set of 1,000 values--ranging from 50 to 150, with a mean of 50 and a standard deviation of 20--was created in order to evaluate the bootstrap method of repeated random sampling. Nine bootstrap samples of N=10 and nine more bootstrap samples of N=25 were randomly selected. One thousand random samples were selected from…

Student's empirical sampling approach is used to assess the magnitude of the sampling errors of statistics describing a recursive causal model. The data were gathered with four complex sample designs commonly used in educational surveys. Jackknife and half-sample error estimates are applied to the data. (Author/CTM)

Sampling distributions for ten tests for comparing population variances in a two group design were generated for several combinations of equal and unequal sample sizes, population means, and group variances when distributional forms differed. The ten procedures included: (1) O'Brien's (OB); (2) O'Brien's with adjusted degrees of freedom; (3)…

The average design effects for statistics estimated from the base-year National Longitudinal Study data are presented. Attempts to partition the effects into those due to stratification, clustering, and unequal weighting are discussed. The expected increases in subpopulation sample sizes due to oversampling are calculated and compared with the…

A self-instructional book covers ten steps toward development of a behavior observation system. Units describe how to interpret graphs, convert information from table to graph form, put collected data into a table, compute the reliability of observational data, make observations with four recording methods, construct an observational system,…

The Colorado Council for Library Development commissioned a state survey to facilitate long range library planning. A survey was designed by Colorado Market Research Services, Inc. and directed to adults throughout the state to ascertain the information needs of the sample population. Citizens were queried as to the frequency of their library use,…

Statistical sampling techniques for the measurement of book readership within libraries are described. The procedures, developed and initially implemented at Rider College, rely upon interviews of book readers inside the library rather than upon such indirect usage measures as which volumes are lift on tables for reshelving, or analyses of user…

This paper discusses distribution theory and power computations for four common "tests of combined significance." These tests are calculated using one-sided sample probabilities or p values from independent studies (or hypothesis tests), and provide an overall significance level for the series of results. Noncentral asymptotic sampling…