We examined the performance of coefficient alpha and its potential competitors (ordinal alpha, omega total, Revelle's omega total [omega RT], omega hierarchical [omega h], greatest lower bound [GLB], and coefficient "H") with continuous and discrete data having different types of non-normality. Results showed the estimation bias was…

When numerous treatments exist for a disease (Treatments 1, 2, 3, etc), network meta-regression (NMR) examines whether each relative treatment effect (eg, mean difference for 2 vs 1, 3 vs 1, and 3 vs 2) differs according to a covariate (eg, disease severity). Two consistency assumptions underlie NMR: consistency of the treatment effects at the…

This note confronts the common use of a single coefficient alpha as an index informing about reliability of a multicomponent measurement instrument in a heterogeneous population. Two or more alpha coefficients could instead be meaningfully associated with a given instrument in finite mixture settings, and this may be increasingly more likely the…

In basketball, game-related statistics are the most common measure of performance. However, the literature assessing their reliability is scarce. Purpose: Analyze the number of games required to obtain a good relative and absolute reliability of teams' game-related statistics. Method: A total of 884 games from the 2015-2016 to 2017-2018 seasons of…

Chalmers recently published a critique of the use of ordinal a[alpha] proposed in Zumbo et al. as a measure of test reliability in certain research settings. In this response, we take up the task of refuting Chalmers' critique. We identify three broad misconceptions that characterize Chalmers' criticisms: (1) confusing assumptions with…

Background: Clinical swallowing assessment is largely limited to qualitative assessment of behavioural observations. There are limited quantitative data that can be compared with a healthy population for identification of impairment. The Test of Masticating and Swallowing Solids (TOMASS) was developed as a quantitative assessment of solid bolus…

The student evaluation of teaching process is generally thought to produce reliable results. The consistency is found within class and instructor averages, while a considerable amount of inconsistency exists with individual student responses. This paper reviews these issues along with a detailed examination of common measures of reliability that…

Differences in rater judgments that are systematically related to construct-irrelevant characteristics threaten the fairness of rater-mediated writing assessments. Accordingly, it is essential that researchers and practitioners examine the degree to which the psychometric quality of rater judgments is comparable across test-taker subgroups.…

Cronbach's alpha is the most frequently used measure to investigate the reliability of measurement instruments. Despite its frequent use, many warn for misinterpretations of alpha. These claims about regular misunderstandings, however, are not based on empirical data. To understand how common such beliefs are, we conducted a survey study to test…

Cohen's kappa coefficient is commonly used for assessing agreement between classifications of two raters on a nominal scale. Three variants of Cohen's kappa that can handle missing data are presented. Data are considered missing if one or both ratings of a unit are missing. We study how well the variants estimate the kappa value for complete data…

Reliable measurements are key to social science research. Multiple measures of reliability of the total score have been developed, including coefficient alpha, coefficient omega, the greatest lower bound reliability, and others. Among these, the coefficient alpha has been most widely used, and it is reported in nearly every study involving the…

In this paper we reflect on the looming question of what constitutes expertise in ethics. Based on an empirical program that involved qualitative and quantitative as well as participatory research elements we show that expertise in research ethics and integrity is based on experience in the assessment processes. We then connect traditional…

We investigate the reliability of data from the Wage Indicator (WI), the largest online survey on earnings and working conditions. Comparing WI to nationally representative data sources for 17 countries reveals that participants of WI are not likely to have been representatively drawn from the respective populations. Previous literature has…

Colleges have increasingly turned to predictive analytics to target at-risk students for additional support. Most of the predictive analytic applications in higher education are proprietary, with private companies offering little transparency about their underlying models. We address this lack of transparency by systematically comparing two…

Supervisors evaluated counselors-in-training at multiple points during their practicum experience using the Counseling Competencies Scale (CCS; N = 1,070). The CCS evaluations were randomly split to conduct exploratory factor analysis and confirmatory factor analysis, resulting in a 2-factor model (61.5% of the variance explained).