As a starting point for their analysis of equity, the authors begin their work here with an examination of the relationship between student performance, as measured by the California Academic Performance Index (API), and student needs, as measured by the percentage of students from low-income families (i.e., the percent of students eligible for…

Many univariate statistical methods assume that dependent variable data have a univariate distribution. Some statistical methods assume that the error scores are normally distributed. It is clear that the concept of data normality is an important one in statistics. This paper explains that, notwithstanding common misconceptions to the contrary,…

Studied the sample coefficient alpha for each of the five subscales of the Hopkins Symptom Checklist (HSL; L. Derogaitis and others, 1974) in a sample of 419 adults. Findings show that the normal-theory-based distribution has a systematic bias in describing the behavior of the sample coefficient alpha. (SLD)

The meta-analysis of coefficient alpha across many studies is becoming more common in psychology by a methodology labeled reliability generalization. Existing reliability generalization studies have not used the sampling distribution of coefficient alpha for precision weighting and other common meta-analytic procedures. A framework is provided for…

This article discusses an international research project that explores teachers' views of a recent learning experience they perceive to have been effective for them. Fourteen teachers attending graduate courses at the University of Washington, USA (six teachers), and the University of Northumbria, UK (eight teachers), form the sample for this…

This study explores a labelling feature that allows students to tag parts of their online messages. Data comes from four sequentially offered sessions of a graduate education course. Students engaged in two to three online activities in groups of three or four. Students (n = 53) contributed from 0 to 56 labels (M = 12.42, SD = 13.50) and 18 to 114…

Grading on the curve is a common practice in higher education. While there are many critics of the practice it still finds wide spread acceptance particularly in science classes. Advocates believe that in large classes student ability is likely to be normally distributed. If test scores are also normally distributed instructors and students tend…

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…