The meta-analytic random effects model assumes that the variability in effect size estimates drawn from a set of studies can be decomposed into two parts: heterogeneity due to random population effects and sampling variance. In this context, the usual goal is to estimate the central tendency and the amount of heterogeneity in the population effect…

This tutorial is concerned with examining how regression to the mean influences research findings in longitudinal studies of clinical populations. In such studies participants are often obtained because of performance that deviates systematically from the population mean and are then subsequently studied with respect to change in the trait used…

Students in statistics service courses are frequently exposed to dogmatic approaches for evaluating the role of randomization in statistical designs, and inferential data analysis in experimental, observational and survey studies. In order to provide an overview for understanding the inference process, in this work some key statistical concepts in…

This paper reviews research based on the psychological autopsy (PA) method applied to the study of suicide. It evidences the presence of a number of methodological problems. Shortcomings concern sampling biases in the selection of control subjects, confounding influences of extraneous variables, and reliability of the assessment instruments. The…

An experiment is described which uses a real-world sample of lawn fertilizer in a simple exercise to illustrate problems associated with the sampling step of a chemical analysis. A mixed-particle fertilizer containing discrete particles of iron oxide (magnetite, Fe[subscript 3]O[subscript 4]) mixed with other particles provides an excellent…

Meehl's taxometric method was developed to distinguish categorical and continuous constructs. However, taxometric output can be difficult to interpret because expected results for realistic data conditions and differing procedural implementations have not been derived analytically or studied through rigorous simulations. By applying bootstrap…

The purpose of this study was to determine whether key elements of high school service learning programs (HSSLPs) cited in the literature were viewed as important by stakeholders in HSSLPs that included students with and without disabilities. Focus groups were conducted with five inclusive HSSLPs selected through purposeful sampling procedures.…

Middle school students' experiences at after-school programs were compared as they participated in different types of activities and with different social partners. The students (N = 165) attended eight programs in three Midwestern states. A total of 1,596 experiences were randomly sampled using the Experience Sampling Method (ESM) during 1 week…

Risks of life on the street caused by inclement weather, harassment, and assault threaten the unsheltered homeless population. We address some challenges of enumerating the street homeless population by testing a novel capture-recapture (CR) estimation approach that models individuals' intermittent daytime visibility. We tested walking and…

The study aimed at finding out whether teachers can identify the courses of reading disabilities in learners. It intended to establish whether teachers have adequate knowledge of identifying learners with reading disabilities, determine the proportion of non-readers in grade five. It also investigated the existing methods and materials teachers…

The Monitoring the Future (MTF) study is an ongoing series of national surveys of American adolescents and adults that has provided the nation with a vital window into the important, but largely hidden, problem behaviors of illegal drug use, alcohol use, tobacco use, anabolic steroid use, and psychotherapeutic drug use. For more than a third of a…

In these days where "accountability" is the byword, organizations more and more frequently seek to evaluate their programs. They often hire outside evaluators to help them assess the effectiveness of their programs, to find out what works and what doesn't, and to determine what programmatic changes would be beneficial. ActKnowledge, a…

The "Where Did They Go?" study, co-funded by the BC Council on Admissions and Transfer (BCCAT) and the Canadian Council on Learning (CCL), was designed to complement research undertaken under the auspices of the Student Transitions Project (STP) which has tracked the public post-secondary participation of BC high school graduates from…

A reasonable expectation of textbooks used in Christian schools is that they should regularly incorporate biblical content. It is also reasonable to expect the biblical content to be integrated--not segregated--to influence matters such as worldview, biblical relevance, character, and integrative skills. This expectation was tested via a…

In this paper an attempt is made to highlight some issues of interpretation of statistical concepts and interpretation of results as taught in undergraduate Business statistics courses. The use of modern technology in the class room is shown to have increased the efficiency and the ease of learning and teaching in statistics. The importance of…