A broad consensus regarding the need for universities to cultivate academic success has emerged because many students do not achieve their goals or optimally benefit from their higher education (HE) experiences (Altbach, 2014; Davidson & Wilson, 2014; Ferrão & Almeida, 2019; Meggiolaro, Giraldo, & Clerici, 2017; Tinto & Pusser,…

Head Start is a national program that helps young children from families with low incomes get ready to succeed in school. It does this by working to promote their early learning and health and their families' well-being. The Head Start Family and Child Experiences Survey (FACES) provides national information about Head Start programs and…

Purpose: Repeated duration data are frequently used in behavioral studies. Classical linear or log-linear mixed models are often inadequate to analyze such data, because they usually consist of nonnegative and skew-distributed variables. Therefore, we recommend use of a statistical methodology specific to duration data. Method: We propose a…

This is the decade of data analytics and big data, but not everyone agrees with the definition of big data. Some researchers see it as the future of data analysis, while others consider it as hype and foresee its demise in the near future. No matter how it is defined, big data for the time being is having its glory moment. The most important…

Visuals and graphics have been used for communicating complex ideas since 1786 when William Playfair first invented the line graph and bar chart. Graphs and charts are useful for interpretation and making sense of data. For instance, John Snow's scatter plot helped pinpoint the source of a cholera outbreak in London in 1854 and also changed…

Since its inception, the National Center for Education Statistics (NCES) has been committed to the practice of documenting its statistical methods for its customers and of seeking to avoid misinterpretation of its published data. The reason for this policy is to assure customers that proper statistical standards and techniques have been observed,…

This guide is designed to help researchers make sure that their research reports include enough information about study measures so that readers can assess the quality of the study's methods and results. The guide also provides examples of write-ups about measures and suggests resources for learning more about these topics. The guide assumes…

Although the past decade has witnessed increased usage of ecological data to map the community-level effects of religion, the vast majority of studies in this body of scholarship continue to be plagued by two key shortcomings. First, ecological research on religion is often conducted in an atheoretical manner, one that privileges the structural…

Written by a social worker for social work students, this is a nuts and bolts guide to statistics that presents complex calculations and concepts in clear, easy-to-understand language. It includes numerous examples, data sets, and issues that students will encounter in social work practice. The first section introduces basic concepts and terms to…

Three linear equating methods for the common item non-equivalent populations design, a design often used in practice, are compared by an analytical method. The models include: (1) Tucker's equally reliable method; (2) Levine's equally reliable methods; and (3) the congeneric method recently introduced by Woodrull (1986). Tucker's method makes…

A Monte Carlo technique was employed in order to compare the relative power and robustness of the Bartlett, Cochran, Hartley, and Levene tests for homogeniety of variance. (Editor)

Since research conclusions derived from inappropriate statistical methodologies can lack accuracy, the article describes a technique appropriate to the heterogeneity of special needs groups in which subjects are assigned to fairly homogeneous subgroups. The technique is related to research in reading with this population. (DB)

Several developments in the use of the new method of meta-analysis give cause for optimism. First, different meta-analysts are doing work in the same areas, leading to increased confidence in meta-analytic results. Second, meta-analysts are beginning to include raw data in their reports, which helps readers pinpoint the exact studies that lead to…

This paper introduces a model for describing outliers (observations which are extreme in some sense or violate the apparent pattern of other observations) in linear regression which can be viewed as a mixture of a quadratic and a linear regression. The maximum likelihood estimators of the parameters in the model are derived and their asymptotic…