Assessed the relative merits of the Student "t" test and the Wilcoxon rank sum test under four population distributions and six sample-size pairings through Monte Carlo methods. The Wilcoxon rank sum test demonstrated an advantage in statistical power for nonnormal distributions (but not normal distributions), with fewer Type III errors…

Discusses four reasons for promoting the use of confidence intervals: (1) ease of interpretation; (2) links with familiar statistical tests; (3) promotion of meta-analytic thinking; and (4) increase of information about precision. Discusses calculations of confidence intervals for a basic standardized effect size measure and discusses software for…

Illustrates the computation of confidence intervals for effect sizes for some analysis of variance applications and shows how the use of intervals involving noncentral distributions is made practical by new software. (SLD)

Status quo approaches to teacher evaluation have recently come under increasing criticism. They typically assign most teachers the highest available score, provide minimal feedback for improvement, and have little connection with student achievement growth and the quality of instruction that leads to higher student growth. A more comprehensive…

The present attempt is to study the use of computer and its possible relationship to Internet attitude, self-efficacy in computer and computer anxiety among higher secondary students. The present study aims at finding the levels of use of computer, Internet attitude, Self-efficacy in computer and computer anxiety among higher secondary students.…

The authors examined the confidence of teachers from Germany, Hong Kong, Italy, and the United States (N = 1,375) to address civic topics with their students. The authors also used differential item functioning models to examine responses to items from the Teacher Confidence Scale of the International Association for the Evaluation of Educational…

Quantiles for finite mixtures of normal distributions are computed. The difference between a linear combination of independent normal random variables and a linear combination of independent normal densities is emphasized. (Contains 3 tables and 1 figure.)

We present empirical data showing that the relative frequency with which a verb normally appears in a syntactic construction predicts young children's ability to remember and repeat sentences instantiating that construction. Children aged 2;10-5;8 years were asked to repeat grammatical and ungrammatical sentential complement sentences (e.g., "I…

This paper is a personal exploration of where the ideas of "distribution" that we are trying to develop in students come from and are leading to, how they fit together, and where they are important and why. We need to have such considerations in the back of our minds when designing learning experiences. The notion of "distribution" as a lens…

A class of multivariate exponential distributions is defined as the distributions of occupancy times in upwards skip-free Markov processes in continuous time. These distributions are infinitely divisible, and the multivariate gamma class defined by convolutions and fractions is a substantial generalization of the class defined by N. L. Johnson and…

This paper evaluated multidimensional linking procedures with which multidimensional test data from two separate calibrations were put on a common scale. Data were simulated with known ability distributions varying on two factors which made linking necessary: mean vector differences and variance-covariance (v-c) matrix differences. After the…

A probability distribution was developed for the Andrews-Pregibon (AP) statistic. The statistic, developed by D. F. Andrews and D. Pregibon (1978), identifies multivariate outliers. It is a ratio of the determinant of the data matrix with an observation deleted to the determinant of the entire data matrix. Although the AP statistic has been used…

The purpose of this report is to demonstrate loglinear smoothing using SAS PROC GENMOD. The results from four published examples, which include the smoothing of a) univariate distributions, b) bivariate distributions, c) distributions with teeth, and d) bivariate distributions with structural zeros, are reproduced to show the flexibility of the…

Two-stage sampling procedures for comparing two population means when variances are heterogeneous have been developed by D. G. Chapman (1950) and B. K. Ghosh (1975). Both procedures assume sampling from populations that are normally distributed. The present study reports on the effect that sampling from non-normal distributions has on Type I error…

Attesting to the continuing economic strength and institutional vitality of the newspaper business in 1987, this booklet presents a statistical summary of the industry in the United States and Canada. The statistics cover a wide range of topics, including (1) number of daily newspapers; (2) daily newspaper circulation; (3) single copy sales price;…