Privatization of support services has been a method that Michigan school districts have used for several years to lower costs. More than ever before, Michigan school districts are privatizing the three main support services they offer--food, custodial and transportation. The annual survey finds that 48.8 percent of Michigan school districts are…

The accuracy of normal approximations to the binomial test was evaluated with and without a continuity correction, regarding control of Type I errors and power. Both tests exhibited substantial power loss in comparison to the exact binomial test, although they are easier to apply and are sometimes desirable. (SLD)

This paper derives a formula for the square of the correlation coefficient in terms of its maximum possible value under rotation of the axes. An application of the formula to quick visual estimation of the correlation coefficient is provided. (TJH)

Greater understanding and use of confidence intervals is central to changes in statistical practice (G. Cumming and S. Finch, 2001). Reliability coefficients and confidence intervals for reliability coefficients can be computed using a variety of methods. Estimating confidence intervals includes both central and noncentral distribution approaches.…

This paper reviews graphical and nongraphical procedures for evaluating multivariate normality by guiding the reader through univariate and bivariate procedures that are necessary, but insufficient, indications of a multivariate normal distribution. A data set using three dependent variables for two groups provided by D. George and P. Mallery…

Developed a sandwich-type covariance matrix to evaluate parameters and provide a rescaled statistic to evaluate a hypothesized general multilevel model. A simulation study with a two-level factor model implies that the rescaled statistic is preferable. (SLD)

Discussion of fractional frequency distributions of authors with a certain (fractional) number of papers focuses on the use of Lotka laws to model theoretical fractional frequency distributions with one parameter. Shows that irregular fractional frequency distributions are a consequence of Lotka's law, not breakdowns of the law. (Author/LRW)

This speculative historiographic essay attempts to fix the present position of library and information science within the context of the probabilistic revolution that has been encompassing all of science. Comprises a guide to statistical research in library and information science, discussing skewed distributions, biostatistics, stochastic models,…

Restricted the range of nonnormal distributions by eliminating scores above a designated cutoff value or eliminating scores above or below the mean by a certain distance. Results of a simulation study show that range restriction sometimes increased the correlation between variables having outlier prone distributions. Discusses practical…

Proposes a procedure for testing hypotheses regarding the dispersion of responses distributed over taxa that uses the distribution of the number of cells that are empty or are singly occupied. Presents a table showing the number of cases needed to achieve 0.10, 0.05, and 0.01 significance for excessive numbers of empty cells. (SLD)

Many textbooks teach a rule of thumb stating that the mean is right of the median under right skew, and left of the median under left skew. This rule fails with surprising frequency. It can fail in multimodal distributions, or in distributions where one tail is long but the other is heavy. Most commonly, though, the rule fails in discrete…

The mean and variance of some continuous distributions, in particular the exponentially decreasing probability distribution and the normal distribution, are considered. Since they involve integration by parts, many students do not feel comfortable. In this note, a technique is demonstrated for deriving mean and variance through differential…

"The Condition of Education 2018" is a congressionally mandated annual report summarizing the latest data on education in the United States. This report is designed to help policymakers and the public monitor educational progress. This report contains indicators on the state of education in the United States, from prekindergarten through…

Measuring the incidence of public spending in education requires an intergenerational framework distinguishing between what current and future generations--that is, parents and children--give and receive. In standard distributional incidence analysis, households are assumed to receive a benefit equal to what is spent on their children enrolled in…

Test statistics based on the assumption that test scores are interval rather than ordinal quality data are questioned. New statistical techniques which do not rely on this assumption are presented. (JKS)