The Behrens-Fisher problem arises when one seeks to make inferences about the means of two normal populations without assuming the variances are equal. This paper presents a review of fundamental concepts and applications used to address the Behrens-Fisher problem under fiducial, Bayesian, and frequentist approaches. Methods of approximations to…

In rebuttal to a critique of the authors' examination of prevalence rate variability for special education categories, it is claimed that a consideration of the nature of prevalence rate data, the correct use of inferential statistics, and the coefficient of variation itself, suggest the objections are not justified. (Author/DB)

Presents an overview of a wide range of measurement models currently available to the analyst who needs to make accurate and valid inferences about respondents and stimuli from data. Reviews models with and without predictor variables or observed and latent predictors, as well as parametric and nonparametric models, and models for order-restricted…

Describes uses of statistical research tools: descriptive statistics, correlation, regression, and inferential statistics. Addresses concerns about statistical analysis in agricultural research. (SK)

The APA Task Force on Statistical Inference recently recommended reporting effect sizes alongside results of statistical significance tests. The purpose of this article is to investigate effect size usage in gifted education research and to follow up on a similar investigation published by Plucker (1997). A content analysis of effect size…

This article describes an illustration of Bayesian inference that has proved popular with students.

The authors provide generalizations of R. J. Boik's (1993) studentized maximum root (SMR) procedure that allow for simultaneous inference on families of product contrasts including simple effect contrasts and differences among simple effect contrasts in coherent analyses of data from 2-factor fixed-effects designs. Unlike the F-based simultaneous…

Annually since 1995, the National Youth Gang Center (NYGC) has conducted the National Youth Gang Survey (NYGS) of law enforcement agencies across the United States regarding the presences and characteristics of local gang problems. This Fact Sheet summarizes NYGS findings from the 2004 survey. The nationally representative sample included the…

The gap between the educational achievements of the comparatively wealthy and those living in poverty is widening world-wide, with the associated threat to social cohesion. Twenty-five years of curriculum reform has largely failed in its objective of providing quality, basic education for all. Arguing that successful innovation requires the…

This paper provides a framework for developing sampling designs in mixed methods research. First, we present sampling schemes that have been associated with quantitative and qualitative research. Second, we discuss sample size considerations and provide sample size recommendations for each of the major research designs for quantitative and…

Purpose: This paper seeks to investigate the provision of Vocational Education and Training (VET) in Small Ethnic Minority Businesses (SEMBs) operating in the West Midlands region of the UK. Design/methodology/approach: A qualitative approach is employed, involving in-depth, face-to-face interviews with 66 owner/managers of small ethnic minority…

It is a common practice in item response theory (IRT) to treat estimates of item parameters, say "B" circumflex, as if they were the known, true quantities, "B." However, ignoring the uncertainty associated with item parameters can lead to biases and over-confidence in subsequent inferences such as ability estimation,…

Describes and compares eight methods of estimating the parameters of the Zipf distribution. (CLB)

This paper asserts that causality is an intriguing but controversial topic in philosophy, statistics, and educational and psychological research. By supporting the Causal Markov Condition and the faithfulness condition, Clark Glymour attempted to draw causal inferences from structural equation modeling. According to Glymour, in order to make…

Regression artifacts are a source of mistaken causal inference in inferences based on time-series data and from longitudinal studies. These artifacts are illustrated, and it is noted that their magnitude is computable (and distinguishable from genuine effects) if the autocorrelation patterns for various lags is known. (SLD)