The fruit fly ("Drosophila melanogaster") is an ideal subject for studying inheritance patterns, Mendel's laws, meiosis, Punnett squares, and other aspects of genetics. Much of what we know about genetics dates to evolutionary biologist Thomas Hunt Morgan's work with mutated fruit flies in the early 1900s. Many genetic laboratories…

In investigations of unusual testing behavior, a common question is whether a specific pattern of responses occurs unusually often within a group of examinees. In many current tests, modern communication techniques can permit quite large numbers of examinees to share keys, or common response patterns, to the entire test. To address this issue,…

As the experience of studying abroad can signal general and transnational human capital, it is considered to be increasingly important for professional careers, particularly in the context of economies' internationalization. However, studies using graduate surveys face problems of self-selection and studies on employers' opinions face problems of…

Nonnormality of univariate data has been extensively examined previously (Blanca et al., 2013; Micceri, 1989). However, less is known of the potential nonnormality of multivariate data although multivariate analysis is commonly used in psychological and educational research. Using univariate and multivariate skewness and kurtosis as measures of…

This study aims to investigate whether the perceived social support and coping styles are predictors of suicide probability by gender. The study was conducted with 445 high schools students, 227 girls, and 218 boys. The participants were aged between 14 and 18, and their average age was 15.90. Data were collected through the "Multidimensional…

Stan is a new Bayesian statistical software program that implements the powerful and efficient Hamiltonian Monte Carlo (HMC) algorithm. To date there is not a source that systematically provides Stan code for various item response theory (IRT) models. This article provides Stan code for three representative IRT models, including the…

In this article, we review four software packages for implementing propensity score analysis in R: "Matching, MatchIt, PSAgraphics," and "twang." After briefly discussing essential elements for propensity score analysis, we apply each package to a data set from the Early Childhood Longitudinal Study in order to estimate the…

Students can struggle to understand and use terms that describe probabilities. Such struggles lead to difficulties comprehending classroom conversations. In this article, we describe some specific misunderstandings a group of students (ages 11-12) held in regard to vocabulary such as "certain", "likely" and…

Power analysis is a fundamental prerequisite for conducting scientific research. Without power analysis the researcher has no way of knowing whether the sample size is large enough to detect the effect he or she is looking for. This paper demonstrates how psychometric factors such as measurement error and equating error affect the power of…

Complex surveys are often used to estimate causal effects regarding the effects of interventions or exposures of interest. Propensity scores (Rosenbaum & Rubin, 1983) have emerged as one popular and effective tool for causal inference in non-experimental studies, as they can help ensure that groups being compared are similar with respect to a…

It is well documented that parental behavior is a strong determinant of a child's educational achievement and general well-being. Thus, it seems relevant to analyze the determinants of parental involvement in the education of their children. While most studies analyze the effect of family characteristics (such as parents' education, ethnicity, or…

The use of a portfolio curriculum approach, when teaching a university introductory statistics and probability course to engineering students, is developed and evaluated. The portfolio curriculum approach, so called, as the students need to keep extensive records both as hard copies and digitally of reading materials, interactions with faculty,…

In this paper, I assess labor market returns of a substantial skill upgrade: college enrollment of the vocationally trained, non-traditional students who do not have the formal entry requirement. Using propensity-score-adjusted regressions and the National Educational Panel Study, I find that these enrollees face high opportunity costs as they…

The purpose of this study was to examine the effects of criteria-referenced formative assessment (CRFA) on students' achievement in theater arts. The role of type of task in differentiating the treatment-achievement relationship was explored. The analytical sample included 520 fifth-grade students from 13 schools in New York City. Schools were…

While it is known that over 500,000 individuals in the State of Indiana have not obtained a High School Diploma or Equivalency (StatsIndiana, 2015), limited empirical information exists on Indiana students pursuing adult basic education along with implications for a state that has changed its adult basic education high stakes high school…