Multivariate analysis of variance (MANOVA) is a statistical method used to examine group differences on multiple outcomes. This article reports results of a review of MANOVA in gifted education journals between 2011 and 2017 (N = 56). Findings suggest a number of conceptual and procedural misunderstandings about the nature of MANOVA and its…

The authors examined the distributional properties of 3 improvement-over-chance, I, effect sizes each derived from linear and quadratic predictive discriminant analysis and from logistic regression analysis for the 2-group univariate classification. These 3 classification methods (3 levels) were studied under varying levels of data conditions,…

Conducted a reliability generalization study of Kolb's Learning Style Inventory (LSI; D. Kolb, 1976). Results for 34 studies indicate that internal consistency and test-retest reliabilities for LSI scores fluctuate considerably and contribute to deleterious cumulative measurement error. (SLD)

Submitted the Mathematics Anxiety Rating Scale (MARS) (F. Richardson and R. Suinn, 1972) to a reliability generalization analysis to characterize the variability of measurement error in MARS scores across administrations and identify characteristics predictive of score reliability variations. Results for 67 analyses generally support the internal…

T. Vacha-Haase (1998) proposed her "reliability generalization" methodology to characterize (a) typical score reliability for a measure across studies, (b) the variability of score reliabilities, and (c) what measurement protocol features predict the variability in score reliabilities across administration. The present article provides…

Studied sources of measurement error variance in the Teacher Efficacy Scale (TES) (Gibson and Dembo, 1984). Used reliability generalization to characterize the typical score reliability for the TES and potential sources of measurement error variance across 43 studies. Also examined related instruments for measurement integrity. (SLD)

Given the potential value of reliability generalization (RG) studies in the development of cumulative psychometric knowledge, the purpose of this paper is to provide a tutorial on how to conduct such studies and to serve as a guide for researchers wishing to use this methodology. After some brief comments on classical test theory, the paper…

Teacher efficacy has proven to be an important variable in teacher effectiveness. It is consistently related to positive teaching behaviors and student outcomes. However, the measurement of this construct is the subject of current debate, which includes critical examination of predominant instruments used to assess teacher efficacy. The present…

Researchers consistently fail to report reliability estimates for data used in their studies. This lack of reporting hinders appropriate evaluation and interpretation of data and may lead to inappropriate conclusions. Because reliability is inured to scores obtained from a test, and not the test itself, it is important to report score reliability…

Although often ignored, reliability is critical when interpreting study effects and test results. Accordingly, this article focuses on the most commonly used estimate of reliability, internal consistency coefficients, with emphasis on coefficient alpha. An interpretive framework is provided for applied researchers and others seeking a conceptual…