Data transformations have been promoted as a popular and easy-to-implement remedy to address the assumption of normally distributed errors (in the population) in linear regression. However, the application of data transformations introduces non-ignorable complexities which should be fully appreciated before their implementation. This paper adds to…

The aim of this paper is to discuss different approaches to the quality (or uncertainty) of measurement data considering both historical examples and today's students' views. Today's teaching of data analysis is very much focussed on the application of statistical routines (often called the "Gaussian approach" to error analysis). Studies on…

Even a casual observer of American college athletics can see the emergence of star black athletes in conferences that once were racially segregated. By analyzing the college origins of National Football League and National Basketball Association draft choices between 1947 and 2011, this research measures the impact of higher education…

This paper explores the nation's changing child population based on data from the 2010 census. While the number of U.S. children increased only slightly, the demographic shifts within the population were considerable. Some areas of the country (Nevada and Texas) and some demographic groups (including children of mixed race) grew significantly,…

Proposition 209 banned the use of racial preferences in admissions at public colleges in California. We analyze unique data for all applicants and enrollees within the University of California (UC) system before and after Prop 209. After Prop 209, graduation rates increased by 4.4%. We present evidence that certain institutions are better at…

The current study examines three regression models: OLS (ordinary least square) linear regression, Poisson regression, and negative binomial regression for analyzing count data. Simulation results show that the OLS regression model performed better than the others, since it did not produce more false statistically significant relationships than…

This study investigated the informal learning experiences expressed by Taiwanese adults (aged from 16 to 97) and examined their involvement related to selected socio-demographic characteristics. Data of the 2008 Adult Education Participation Survey in Taiwan and Fujian Area were used to look at different variables of adults' demographic…

Students who take classes in education departments at universities receive significantly higher grades than students who take classes in other academic departments. The higher grades awarded by education departments cannot be explained by differences in student quality or by structural differences across departments (i.e., differences in class…

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…

Outliers, extreme data values relative to others in a sample, may distort statistics that assume internal levels of measurement and normal distribution. The outlier may be a valid value or an error. Several procedures are available for identifying outliers, and each may be applied to errors of prediction from the regression lines for utility in a…

Glass's estimator of effect size, the sample mean difference divided by the sample standard deviation, is studied in the context of an explicit statistical model. The exact distribution of Glass's estimator is obtained and the estimator is shown to have a small sample bias. Alternatives are proposed and discussed. (Author/JKS)

Model-based methods for estimating the population mean in stratified clustered sampling are described. The importance of adjusting the weights is assessed by an approach considering the sampling variation of the adjusted weights and its (variance) components. The resulting estimators are more efficient than the jackknife estimators for a variety…

Global economic transformations have never been as dramatic as in the twentieth century. Most countries have experienced radical changes in the standards of income per capita, technology, fertility, mortality, income inequality and the extent of democracy in the course of the past century. It is the goal of many disciplines--economics, history,…

Variability stands in the heart of statistics theory and practice. Concepts and judgments involved in comparing groups have been found to be a productive vehicle for motivating learners to reason statistically and are critical for building the intuitive foundation for inferential reasoning. The focus in this paper is on the emergence of beginners'…