Retrospective or post hoc power analysis is recommended by reviewers and editors of many journals. Little literature has been found that gave a serious study of the post hoc power. When the sample size is large, the observed effect size is a good estimator of the true power. This article studies whether such a power estimator provides valuable…

Purpose: The aim of this work is to implement bootstrapping methods into software tools, based on Java. Design/methodology/approach: This paper presents a category of software e-tools aimed at simulating laboratory works and experiments. Findings: Both students and teaching staff use traditional statistical methods to infer the truth from sample…

The primary purpose of this study was to examine significant differences, if any, in student achievement in the area of math and science of students taught by traditionally certified teachers and alternatively certified teachers. This study examined alternatively certified teachers, as identified from through the Georgia TAPP (Teacher Alternative…

This study is the fourth in a series of studies conducted by the American Association of School Administrators on the impact of the economic downturn on schools. AASA launched the series in fall 2008 in response to state budget shortfalls, federal buy-outs and interventions, and a series of additional events characterizing a slowing, stagnant…

The National Survey of Student Engagement (NSSE) provides participating schools an Institutional Report that includes (among many documents) mean comparisons, frequency distributions, and student respondent data as part of its standard reporting package. Sifting through all this data can leave even experienced researchers wondering where to start…

Given the fragmented structure of child-care assistance in the United States, it has been difficult to obtain accurate estimates of which families are assisted, through which mechanisms, and at what level. Making use of survey data from New York City, we analyze the distribution of several forms of public child-care assistance. Results suggest…

Comparing variability of test scores across alternate forms, test conditions, or subpopulations is a fundamental problem in psychometrics. A confidence interval for a ratio of standard deviations is proposed that performs as well as the classic method with normal distributions and performs dramatically better with nonnormal distributions. A simple…

The notion of optimality is often invoked informally in the literature on metacognitive control. We provide a precise formulation of the optimization problem and show that optimal time allocation strategies depend critically on certain characteristics of the learning environment, such as the extent of time pressure, and the nature of the uptake…

The Mantel-Haenszel (MH) procedure has become one of the most popular procedures for detecting differential item functioning (DIF). One of the most troublesome criticisms of this procedure is that while detection rates for uniform DIF are very good, the procedure is not sensitive to non-uniform DIF. In this study, examinee responses were generated…

The extent to which properties of the ability scale and the form of the latent trait distribution influence the estimated item parameters of item response theory (IRT) was investigated using real and simulated data. Simulated data included 5,000 ability values randomly drawn from the standard normal distribution. Real data included the results for…

Designed to provide librarians, library administrators, and other interested persons with information organized to facilitate comparisons of libraries within the same library system, with comparable service populations, and with comparable expenditures, this publication contains information derived from the 1985 Annual Report/System Membership…

Most currently used measures of inter-rater agreement for the nominal case incorporate a correction for "chance agreement." The definition of chance agreement is not the same for all coefficients, however. Three chance-corrected coefficients are Cohen's Kappa; Scott's Pi; and the S index of Bennett, Goldstein, and Alpert, which has…

This report provides a general overview of available courseware for computer assisted instruction by examining the distribution of these packages across grade level, hardware type, instructional mode, and subject areas, including art, business education, computer science, language arts, foreign language, mathematics, science, social studies,…

This study examined the sampling distribution of the analysis of variance F ratio in the two sample cases when it followed a preliminary test for variance equality. When the population variances were equal, the sampling distribution approximated the theoretical F distribution quite well, but not when population variances differed. (JAZ)

E. Burns' (1984) attempt to explain the below average mean IQ scores reported for samples of learning dsabled (LD) students through the use of the bivariate normal probability distribution was examined. Alternative explanations which focus on issues related to the referral, identification, and placement of children are presented.(Author)