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…

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…

Extensive education research on the contribution of teachers to student achievement produces two generally accepted results. First, teacher quality varies substantially as measured by the value added to student achievement or future academic attainment or earnings. Second, variables often used to determine entry into the profession and…

An analysis was conducted to identify sources of true and error variance in measuring swimming drag force to draw valid conclusions about performance factor effects. Passive drag studies were grouped according to methodological differences: tow line in pool, tow line in flume, and carriage in tow tank. Active drag studies were grouped according to…

This Monte Carlo study examined the impact of misspecifying the [big sum] matrix in longitudinal data analysis under both the multilevel model and mixed model frameworks. Under the multilevel model approach, under-specification and general-misspecification of the [big sum] matrix usually resulted in overestimation of the variances of the random…

This study aimed at estimating the correlation between true scores (true consistency) of vocational interest over a short time span in a sample of 1089 adults. Participants were administered 54 items assessing vocational, family, and leisure interests twice over a 1-month period. Responses were analyzed with a multitrait (MT) model, which supposes…

One of the major problems that a tree-approach to data analysis often encounters is the instability of tree-structures. The instability issue must be dealt with before data can be interpreted by this method. Examining instability at a node of a tree provides insight into the instability of the whole tree, because the same theory of instability…