The effects of sampling biases upon research studies requiring different time commitments of Ss in mother-infant studies were examined. Twenty mothers who participated in 35 hours of observation were compared with 17 mothers who refused to participate but completed a questionnaire. Questionnaire responses did not differentiate the two groups.…

Factors that influence the sample size necessary for longitudinal evaluations include the nature of the evaluation questions, nature of available comparison groups, consistency of the treatment in different sites, effect size, attrition rate, significance level for statistical tests, and statistical power. (Author/GDC)

Computer simulations were employed to investigate sample sizes needed for item analysis when one's primary purpose is to rank order items in terms of indices of quality or to compare indices of quality against a fixed criterion. Necessary sample sizes were much smaller than those indicated by the literature. (Author/JKS)

A Monte Carlo technique was used to investigate the effect of the differences in covariate means among treatment groups on the significance level and the power of the F-test of the analysis of covariance. (Author/GDC)

A computer program to generate individualized objective test forms for use in a Student Faced Statistics (SPS) course is described. The program features disproportionate sampling from different item domains and enhanced character generation facility for test printing purposes. (Author)

An expanded multiple matrix sampling procedure to collect assessment data for health education courses in upper elementary and junior high schools is outlined. This supplement to the Cooperative Health Education Test provides data at the school building and district levels. (JMF)

Flexibility in evaluative research design does not necessitate the abandonment of randomly constructed comparison groups. Three designs are reviewed which provide at least the option of randomization while maintaining great flexibility. The strengths and weaknesses of the designs are discussed. (Author)

This study demonstrates that multiple matrix sampling procedures can be used to collect assessment data efficiently, unabstrusively, and reliably. (MB)

The relationships between class of degree in psychology from one department and (a) interview ratings, (b) two adult intelligence tests, and (c) advanced-level examinations were examined in a sample of 145 students from four-year groups. (Editor)

Discusses ethical issues surrounding passive and active parental consent procedures when minors are to be asked sensitive research questions, exploring parental rights and the effect of active consent procedures on response rates and sample bias. Response rates are reported from two studies in which active consent procedures were implemented. (SLD)

Using the characteristic curve method for dichotomously scored test items, the sampling distributions of equating coefficients were examined. Simulations indicate that for the equating conditions studied, the sampling distributions of the equating coefficients appear to have acceptable characteristics, suggesting confidence in the values obtained…

Describes the role and function of the census and discusses census taking and decision making about "counting" from two perspectives: the Supreme Court decision in Wisconsin vs New York, and the Census Bureau's current plans for the year 2000. Concluding comments explore the lessons learned from the 1990 census and the effect on the 2000…

An Edgeworth approximation for accurate significance probabilities for the Wilcoxon two-sample test is substantially simplified. A method is developed that allows quick calculations of very accurate probabilities. Exact formulas are given for most of the remaining cases, and tables are presented comparing the new simplification to likely…

A Monte Carlo study involving 1,000 random samples from each of 64 different population matrices investigated bias in both canonical correlation and redundancy coefficients. Results indicate that the Wherry correction provides a reasonable solution to this problem and that canonical results are not as biased as has been believed. (TJH)

Two computer-intensive procedures are presented for dealing with non-random selection in the development of samples for experimental, quasi-experimental, and survey designs associated with educational research. The procedures are randomization tests to clarify treatment effects and bootstrap techniques to estimate the uncertainty of…