Sample size and statistical power are important factors to consider when planning a research synthesis. Power analysis methods have been developed for fixed effect or random effects models, but until recently these methods were limited to simple data structures with a single, independent effect per study. Recent work has provided power…

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…

The identification of evidence-based practices continues to provoke issues of disagreement across multiple fields. One area of contention is the role of single-subject design (SSD) research in providing scientific evidence. The debate about SSD's utility centers on three issues: sample size, effect size, and serial dependence. One potential…

Educational researchers commonly use the rule of thumb of "design effect smaller than 2" as the justification of not accounting for the multilevel or clustered structure in their data. The rule, however, has not yet been systematically studied in previous research. In the present study, we generated data from three different models…

The study investigated the relationship between vocational interest socio-economic status and re-entry of girls into school in Edo State. The research design adopted was correlational because it sought to establish the relationship between the independent variable and the dependent variable. A sample size of 306 girls who re-enrolled in institutes…

Background: A meta-analysis examined the effects of deinstitutionalisation on adaptive behaviour outcomes in persons with intellectual disability. The need for an updated review in this area is reflected by recent policy shifts in community care practices and the international status of deinstitutionalisation efforts. Method: Twenty-three studies…

This study explored the influence of strengths-based development on leadership practices among undergraduate college students while controlling for gender, years of leadership experience, and number of completed leadership courses using a quasi-experimental approach with a randomized control-group pretest-posttest research design. The sample…

Arguments have recently been put forth that standard textbook procedures for determining the sample size necessary to achieve a certain level of power in a completely randomized design are incorrect when the dependent variable is fallible because they ignore measurement error. In fact, however, there are several correct procedures, one of which is…

Magnitude of effect measures (MEMs), when adequately understood and correctly used, are important aids for researchers who do not want to rely solely on tests of statistical significance in substantive result interpretation. The MEM tells how much of the dependent variable can be controlled, predicted, or explained by the independent variables.…

An evaluation of the rules-of-thumb used to determine the minimum number of subjects required to conduct multiple regression analyses suggests that researchers who use a rule of thumb rather than power analyses trade simplicity of use for accuracy and specificity of response. Insufficient power is likely to result. (SLD)

An efficiency study was conducted of the base year design used for the National Longitudinal Study of the High School Class of 1972 (NLS). Finding the optimal design involved a search for the numbers of sample schools and students that would maximize the variance at a given cost. Twenty-one variables describing students' plans, attitudes,…

An efficiency study was conducted of the sampling design used for the National Longitudinal Study of the High School Class of 1972 (NLS), and the change variables used in the first followup. Nine alternative designs were compared, using a cost model based upon the number of schools and students sampled. Fourteen change variables and eight domains…

A meta analysis was conducted of studies of college students' evaluations of their teachers. Forty-seven studies were included, representing 74 multisection courses, in which four selection criteria were met. An actual, rather than an experimental class was used; the unit of analysis was the class rather than the individual student; a common…