Cronbach's alpha estimates the internal consistency of responses in multi-item bipolar scales. This article examined three research questions (RQ): (1) To what extent do inconsistencies exist in data ...(e.g., responses of −2 −2 2 2)? (2) Does the number of scale items influence the amount of inconsistency? (3) Does Cronbach's alpha mask inconsistencies? Data were obtained from 29 research projects (n = 10,616). Each survey had place attachment questions comprising two concepts: place identity and place dependence. Respondents were classified as consistent or inconsistent based on their responses to the place attachment questions. Results demonstrated that: (a) inconsistent response patterns existed in the data (RQ1), (b) number of scale items influenced amount of inconsistency (RQ2), and (c) alpha masked these inconsistencies (RQ3). Discussion focused on implications of these findings.
Abstract
Empirical studies in psychology commonly report Cronbach's alpha as a measure of internal consistency reliability despite the fact that many methodological studies have shown that Cronbach's ...alpha is riddled with problems stemming from unrealistic assumptions. In many circumstances, violating these assumptions yields estimates of reliability that are too small, making measures look less reliable than they actually are. Although methodological critiques of Cronbach's alpha are being cited with increasing frequency in empirical studies, in this tutorial we discuss how the trend is not necessarily improving methodology used in the literature. That is, many studies continue to use Cronbach's alpha without regard for its assumptions or merely cite methodological articles advising against its use to rationalize unfavorable Cronbach's alpha estimates. This tutorial first provides evidence that recommendations against Cronbach's alpha have not appreciably changed how empirical studies report reliability. Then, we summarize the drawbacks of Cronbach's alpha conceptually without relying on mathematical or simulation-based arguments so that these arguments are accessible to a broad audience. We continue by discussing several alternative measures that make less rigid assumptions which provide justifiably higher estimates of reliability compared to Cronbach's alpha. We conclude with empirical examples to illustrate advantages of alternative measures of reliability including omega total, Revelle's omega total, the greatest lower bound, and Coefficient H. A detailed software appendix is also provided to help researchers implement alternative methods.
Translational Abstract
Scales are commonly used in psychological research to measure directly unobservable constructs like motivation or depression. These scales are comprised of multiple items, each aiming to provide information about various aspects of the construct of interest. Whenever a scale is used in a psychological study, it is important to report on its reliability. Since the 1950s, the primary method for capturing reliability has been Cronbach's alpha, a method whose status is perhaps best exemplified by its place as one of the most cited scientific articles of all-time, in any field. Despite its overwhelming popularity, the underlying assumptions of Cronbach's alpha have been questioned recently in the statistical literature because these assumptions were commonplace 65 years ago but have largely disappeared from more modern statistical methods for constructing scales. Though the ideas in these statistical articles have the potential to significantly alter how psychological research is conducted and reported, recommendations from the statistical literature have yet to permeate the psychological literature. In this article, the goal is to demonstrate why Cronbach's alpha is no longer the optimal method for reporting on reliability. To differentiate this article from articles appearing in the statistical literature, we approach issues with Cronbach's alpha with very little focus on mathematical or computational detail so that the deficiencies of Cronbach's alpha are illustrated in words and examples rather than proofs and simulations so that these ideas can impact a larger group of researchers-namely, the researchers who most often report Cronbach's alpha.
En este trabajo se presenta una guía conceptual y práctica para estimar la fiabilidad de consistencia interna de medidas obtenidas mediante suma o promedio de ítems con base en las aportaciones más ...recientes de la psicometría. El coeficiente de fiabilidad de consistencia interna se presenta como un subproducto del modelo de medida subyacente en las respuestas a los ítems y se propone su estimación mediante un procedimiento de análisis de los ítems en tres fases, a saber, análisis descriptivo, comprobación de los modelos de medida pertinentes y cálculo del coeficiente de consistencia interna y su intervalo de confianza. Se proporcionan las siguientes fórmulas: (a) los coeficientes alfa de Cronbach y omega para medidas unidimensionales con ítems cuantitativos (b) los coeficientes omega ordinal, alfa ordinal y de fiabilidad no lineal para ítems dicotómicos y ordinales, y (c) los coeficientes omega y omega jerárquico para medidas esencialmente unidimensionales con efectos de método. El procedimiento se generaliza al análisis de medidas obtenidas por suma ponderada, de escalas multidimensionales, de diseños complejos con datos multinivel y/o faltantes y también al desarrollo de escalas. Con fines ilustrativos se expone el análisis de cuatro ejemplos numéricos y se proporcionan los datos y la sintaxis en R.
Coefficient α, although ubiquitous in the research literature, is frequently criticized for being a poor estimate of test reliability. In this note, we consider the range of α and prove that it has ...no lower bound (i.e., α ∈ ( - ∞, 1). While outlining our proofs, we present algorithms for generating data sets that will yield any fixed value of α in its range. We also prove that for some data sets-even those with appreciable item correlations-α is undefined. Although α is a putative estimate of the correlation between parallel forms, it is not a correlation as α can assume any value below-1 (and α values below 0 are nonsensical reliability estimates). In the online supplemental materials, we provide R code for replicating our empirical findings and for generating data sets with user-defined α values. We hope that researchers will use this code to better understand the limitations of α as an index of scale reliability. (PsycInfo Database Record (c) 2023 APA, all rights reserved).
An Ultra-Short Measure for Work Engagement Schaufeli, Wilmar B; Shimazu, Akihito; Hakanen, Jari ...
European journal of psychological assessment : official organ of the European Association of Psychological Assessment,
2019, Letnik:
35, Številka:
4
Journal Article
Recenzirano
Odprti dostop
The current study introduces an ultra-short, 3-item
version of the Utrecht Work Engagement Scale. Using five national samples from
Finland (N = 22,117), Japan
(N = 1,968), the Netherlands
...(N = 38,278), Belgium/Flanders
(N = 5,062), and Spain
(N = 10,040) its internal consistency and
factorial validity vis-à-vis validated measures of burnout, workaholism,
and job boredom are demonstrated. Moreover, the UWES-3 shares 86-92% of
its variance with the longer nine-item version and the pattern of correlations
of both versions with 9 indicators of well-being, 8 job demands, 10 job
resources, and 6 outcomes is highly similar with an average, absolute difference
between correlations of only .02. Hence, it is concluded that the UWES-3 is a
reliable and valid indicator of work engagement that can be used as an
alternative to the longer version, for instance in national and international
epidemiological surveys on employee's working conditions.
Cronbach’s alpha is a very commonly used method in biomedical research. Cronbach’s alpha Indicates the extent to which the items in your questionnaire are related to each other, a useful coefficient ...for assessing the internal consistency of the items. Although this method is commonly used in medical research, the statistical software packages do not have the direct menu-driven operation for Cronbach’s alpha. Hence this paper intends to provide an R function (Cronbach. Alpha) for Cronbach’s alpha analysis.
Cronbach’s Coefficient Alpha Cho, Eunseong; Kim, Seonghoon
Organizational research methods,
04/2015, Letnik:
18, Številka:
2
Journal Article
Recenzirano
This study disproves the following six common misconceptions about coefficient alpha: (a) Alpha was first developed by Cronbach. (b) Alpha equals reliability. (c) A high value of alpha is an ...indication of internal consistency. (d) Reliability will always be improved by deleting items using “alpha if item deleted.” (e) Alpha should be greater than or equal to .7 (or, alternatively, .8). (f) Alpha is the best choice among all published reliability coefficients. This study discusses the inaccuracy of each of these misconceptions and provides a correct statement. This study recommends that the assumptions of unidimensionality and tau-equivalency be examined before the application of alpha and that structural equation modeling (SEM)–based reliability estimators be substituted for alpha when one of these conditions is not satisfied. This study also provides formulas for SEM-based reliability estimators that do not rely on matrix notation and step-by-step explanations for the computation of SEM-based reliability estimates.
•This the first meta-analytic study providing a quantitative estimate of the overall internal consistency and temporal stability of the CAPE-42, CAPE-20, CAPE-P15 and CAPE-P8.•Results show that the ...CAPE, across its different versions and languages, is a highly reliable and consistent measure for the assessment of psychotic experiences in both clinical and non-clinical populations.•We identified that information on the temporal stability of the CAPE is scant, which is critical due to the importance of recurring PE in the progression towards severe mental disorders in both general and clinical populations.
Psychotic experiences (PE) are prevalent in general and clinical populations and can increase the risk for mental disorders in young people. The Community Assessment of Psychic Experiences (CAPE) is a widely used measure to assess PE in different populations and settings. However, the current knowledge on their overall reliability is limited. We examined the reliability of the CAPE-42 and later versions, testing the role of age, sex, test scores, and clinical status as moderators. A systematic search was conducted on the Scopus, Web of Science, PubMed, EBSCOhost, ProQuest, and GoogleScholar databases. Internal consistency and temporal stability indices were examined through reliability generalization meta-analysis (RGMA). Moderators were tested through meta-regression analysis. From a pool of 1,015 records, 90 independent samples were extracted from 71 studies. Four versions showed quantitative evidence for inclusion: CAPE-42, CAPE-20, CAPE-P15, and CAPE-P8. Internal consistency indices were good (α/ω≈.725–0.917). Temporal stability was only analyzed for the CAPE-P15, yielding a moderate but not-significant effect (r=0.672). The evidence for temporal stability is scant due to the limited literature, and definitive conclusions cannot be drawn. Further evidence on other potential moderators such as adverse experiences or psychosocial functioning is required.
Due to advances in technology, routine seawater pH measurements of excellent repeatability are becoming increasingly common for studying the ocean CO2 system. However, the accuracy of pH measurements ...has come into question due to a widespread observation, from a large number of carefully calibrated state-of-the-art CO2 measurements on various cruises, of there being a significant pH-dependent discrepancy between pH that was measured spectrophotometrically and pH calculated from concurrent measurements of total dissolved inorganic carbon (CT) and total alkalinity (AT), using a thermodynamic model of seawater acid-base systems. From an analysis of four recent GO-SHIP repeat hydrography datasets, we show that a combination of small systematic errors in the dissociation constants of carbonic acid (K1 and K2), the total boron-salinity ratio, and in CT and AT measurements are likely responsible for some, but not all of the observed pH-dependent discrepancy. The residual discrepancy can only be fully accounted for if there exists a small, but meaningful amount (~4 μmol kg–1) of an unidentified and typically neglected contribution to measured AT, likely from organic bases, that is widespread in the open ocean. A combination of these errors could achieve consistency between measured and calculated pH, without requiring that any of the shipboard measurements be significantly in error. Future research should focus on establishing the existence of organic alkalinity in the open ocean and constraining the uncertainty in both CO2 measurements and in the constants used in CO2 calculations.
•The thermodynamic consistency of CO2 system measurements was investigated.•Errors in CO2 measurements are unlikely to be the main cause of inconsistencies.•There are likely systematic errors in K1, K2, and the total boron-salinity ratio.•An unaccounted source of alkalinity may be present in the open ocean.
The development of scientific research on social support in Mexico has been limited, partly due to the lack of specific instruments about the sports environment. In response to this measurement ...necessity, the present study aims to analyze the evidence of validity and reliability of the Perceived Available Support in Sport Questionnaire (PASS-Q) in Mexican athletes. The sample was composed of 991 athletes, with ages between 12 and 32 years. Through Confirmatory factor analysis, it was obtained enough evidence for construct validity. The adjustment indexes used to evaluate the PASS-Q four-factor model seem to fit well (χ2 = 474.949; fg = 88; p < .01; CFI = 0.96; TLI = 0.94; IFI = 0.96; RMSEA = 0.07). The standardized factor loadings were statistically significant, exceeding the minimum recommended value (λ = 0.40). Regarding discriminant and concurrent validity, empirical support was found for the correlations of the PASS-Q with the ABQ and the SPSS. The reliability was high with Cronbach's alpha coefficient between 0.81 and 0.84. The tetrafactorial model demonstrated configural, metric and scalar invariance in relation to gender. The PASS-Q shows adequate psychometric properties and its use with Mexican athletes is recommended.
El estudio científico del apoyo social en México se ha visto limitado en su desarrollo, en parte debido a la falta de instrumentos específicos del contexto deportivo. Atendiendo a estas demandas de medición, el objetivo de esta investigación fue analizar la evidencia de validez y fiabilidad del Perceived Available Support in Sport Questionnaire (PASS-Q) en deportistas mexicanos. Participaron 991 deportistas (hombres = 66.3%) entre 12 y 32 años de edad (M = 17.22, DT = 2.83). Mediante el Análisis factorial confirmatorio se obtuvo suficiente evidencia de la validez de constructo. Los índices de bondad de ajuste del modelo tetrafactorial del PASS-Q fueron aceptables (χ2 = 474.949; χ2/df = 5.39; df = 88; p < .01; CFI = 0.96; TLI = 0.94; IFI = 0.96; RMSEA = 0.07). Las cargas factoriales estandarizadas resultaron estadísticamente significativas, superando el valor mínimo recomendado (λ = 0.40). En cuanto a la validez discriminante y concurrente, se encontró respaldo empírico a las correlaciones del PASS-Q con el ABQ y la SPSS. La fiabilidad fue alta con coeficientes alfa de Cronbach entre 0.81 y 0.84. El modelo tetrafactorial demostró invarianza configural, métrica y escalar en relación al género. El PASS-Q muestra adecuadas evidencias de validez y fiabilidad, recomendando su uso con deportistas mexicanos.
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