Proposes the use of statistical power subsequent to the results of hypothesis testing in business research. Describes how posttest use of power might be integrated into business statistics courses. (SK)

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)

Markov models provide a general framework for analyzing and interpreting time dependencies in psychological applications. Recent work extended Markov models to the case of latent states because frequently psychological states are not directly observable and subject to measurement error. This article presents a further generalization of latent…

A covariance structure modeling method to test equality in proportions explained variance in studied unobserved dimensions by means of latent predictors is outlined. The procedure is applicable with multiple-indicator, structural equation models where of interest is to compare the predictive power of sets of latent independent variables for given…

The authors describe and illustrate 6 factors that affect the size of a Pearson correlation: (a) the amount of variability in the data, (b) differences in the shapes of the 2 distributions, (c) lack of linearity, (d) the presence of 1 or more "outliers," (e) characteristics of the sample, and (f) measurement error. Also discussed are ways to…

The recent development of multilevel IRT models (Fox & Glas, 2001, 2003) has been shown to be very useful for analyzing relationships between observed variables on different levels containing measurement error. Model parameter estimates and their standard deviations are concurrently estimated taking account of measurement error in observed…

When errors of measurement are positively correlated, coefficient alpha may overestimate the "true" reliability of a composite. To reduce this inflation bias, Komaroff (1997) has proposed an adjusted alpha coefficient, ak. This article shows that ak is only guaranteed to be a lower bound to reliability if the latter does not include correlated…

Discretized multivariate normal structural models are often estimated using multistage estimation procedures. The asymptotic properties of parameter estimates, standard errors, and tests of structural restrictions on thresholds and polychoric correlations are well known. It was not clear how to assess the overall discrepancy between the…

There is great controversy in the field of learning disabilities (LD) regarding the establishment of criteria for LD identification. The traditional approach to LD identification is to use the IQ-discrepancy. Lyon and colleagues (2001) point out the numerous problems with such an approach, including faulty assumptions about the adequacy of an IQ…

This article considers models involving a single structural equation with latent explanatory and/or latent dependent variables where discrete items are used to measure the latent variables. Our primary focus is the use of scores as proxies for the latent variables and carrying out ordinary least squares (OLS) regression on such scores to estimate…

The testing of English language learners (ELLs) is, to a large extent, a random process because of poor implementation and factors that are uncertain or beyond control. Yet current testing practices and policies appear to be based on deterministic views of language and linguistic groups and erroneous assumptions about the capacity of assessment…

This paper examines the estimation of two-stage clustered RCT designs in education research using the Neyman causal inference framework that underlies experiments. The key distinction between the considered causal models is whether potential treatment and control group outcomes are considered to be fixed for the study population (the…

Using "error bars" on graphs is a good way to help students see that, within the inherent uncertainty of the measurements due to the instruments used for measurement, the data points do, in fact, lie along the line that represents the linear relationship. In this article, the author explains why connecting the dots on graphs of collected data is…

This study examines the effects of kindergarten retention on children's social-emotional development in the early, middle, and late elementary years. Previous studies have generated mixed results partly due to some major methodological challenges, including selection bias, measurement error, and divergent perceptions of multiple respondents in…

In light of a recent revelation that Gersten (1985) included erroneous information on one of two programs for English Language Learners (ELLs), the authors re-calculate results of their earlier meta-analysis of program effectiveness studies for ELLs in which Gersten's studies had behaved as outliers (Rolstad, Mahoney & Glass, 2005). The correction…