The DOI matches its Crossref record; 25 of the 26 references it cites were found in a registry or an index.
What is coefficient alpha? An examination of theory and applications
Abstract
Psychological research involving scale construction has been hindered considerably by a wide-spread lack of understanding of coefficient alpha and reliability theory in general. A discussion of the assumptions and meaning of coefficient alpha is presented. This discussion is followed by a demonstration of the effects of test length and dimensionality on alpha by calculating the statistic for hypothetical tests with varying numbers of items, numbers of orthogonal dimensions, and average item intercorrelations. Recommendations for the proper use of coefficient alpha are of-fered. Coefficient alpha (Cronbach, 1951) is certainly one of the most important and pervasive statistics in research involving test construction and use. A review of the Social Sciences Cita-tions Index for the literature from 1966 to 1990 revealed that Cronbach's (1951) article had been cited approximately 60 times per year and in a total of 278 different journals. In addi-tion to the areas of psychology in which one may expect to see alpha used, such as educational, industrial, social, clinical, child, community, and abnormal psychology, this list of jour-nals included representatives from experimental psychology, so-ciology, statistics, medicine, counseling, nursing, economics,
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“The reliability of each scale was tested with the Cronbach's Alpha: all the values are over 0.7, which implies that there is an overall adequate internal consistency and that the measures could be considered reliable (Cortina, 1993;Taber, 2017).”
From The self-reinforcing effect of digital and social exclusion: The inequality loop (2022) · cites this paper as Cortina, 1993
In the citing paper
“Internal consistency reliability (Cronbach’s alpha) ranged from 0.70 to 0.79, which is within what is generally considered the acceptable range of 0.65–0.80 [47,48]”
From Gender Differences in Coping and Psychological Adaptation during the COVID-19 Pandemic (2023) · cites this paper as [47]
In the citing paper
“We chose these two tools, instead of traditional measures of internal consistency (i.e., Cronbach's Alpha [Cronbach, 1951] or KR-20 for dichotomous data [Kuder and Richardson, 1937]) because unlike traditional estimates which do not assess homogeneity (Cortina, 1993; Clark and Watson, 1995), omega and CFA, simultaneously provide estimates of both.”
From A psychometric analysis of the reading the mind in the eyes test: toward a brief form for research and applied settings (2015) · cites this paper as Cortina, 1993
In the citing paper
“Also, Cronbach's alpha is highly biased by long tests; Cortina (1993) recommended Cronbach's alpha not be used for tests with more than 40 items and the Eyes Test, at 36 items, is close to this limit.”
From A psychometric analysis of the reading the mind in the eyes test: toward a brief form for research and applied settings (2015) · cites this paper as Cortina, 1993
In the citing paper
“Reliability estimates are biased towards number of items, and on scales with small numbers of items the alpha is a poor indicator of measure fit (Cortina 1993).”
From Sleep Problems Across Development: A Pathway to Adolescent Risk Taking Through Working Memory (2015) · cites this paper as Cortina 1993
Citations
Cites
Coefficient Alpha and the Internal Structure of Tests
Cronbach, L. J. (1951) · Psychometrika · doi:10.1007/bf02310555 · Cited by 43,931
Psychometric theory (2nd ed.).
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Introduction to Measurement Theory
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The Dependability of Behavioral Measurements: Theory of Generalizability for Scores and Profiles
Merrifield, P. R., Cronbach, L. J., Gleser, G. C., Nanda, H., & Rajaratnam, N. (1974) · American Educational Research Journal · doi:10.2307/1162145 · Cited by 1,819
CORRELATION CALCULATED FROM FAULTY DATA
Spearman, C. (1910) · British Journal of Psychology 1904-1920 · doi:10.1111/j.2044-8295.1910.tb00206.x · Cited by 1,215
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SOME EXPERIMENTAL RESULTS IN THE CORRELATION OF MENTAL ABILITIES 1
Brown, W. E. (1910) · British Journal of Psychology 1904-1920 · doi:10.1111/j.2044-8295.1910.tb00207.x · Cited by 733
Limitations of Coefficient Alpha as an Index of Test Unidimensionality1
Green, S. B., Lissitz, R. W., & Mulaik, S. A. (1977) · Educational and Psychological Measurement · doi:10.1177/001316447703700403 · Cited by 522
Test “Reliability”: Its Meaning and Determination
Cronbach, L. J. (1947) · Psychometrika · doi:10.1007/bf02289289 · Cited by 469
COEFFICIENT ALPHA AND THE RELIABILITY OF COMPOSITE MEASUREMENTS
Novick, M. R., & Lewis, C. (1966) · ETS Research Bulletin Series · doi:10.1002/j.2333-8504.1966.tb00356.x · Cited by 445
A K-Sample Significance Test for Independent Alpha Coefficients
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Number of Scale Points and the Reliability of Scales
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Principles of research in social psychology
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THE SYMMETRY OF GENERALIZABILITY THEORY: APPLICATIONS TO EDUCATIONAL MEASUREMENT
Cardinet, J., TOURNEUR, W., & Allal, L. K. (1976) · Journal of Educational Measurement · doi:10.1111/j.1745-3984.1976.tb00003.x · Cited by 129
A Series of Lower Bounds to the Reliability of a Test
ten Berge, J. M. F., & Zegers, F. E. (1978) · Psychometrika · doi:10.1007/bf02293815 · Cited by 75
A Measure of the Average Intercorrelation
Kaiser, H. F. (1968) · Educational and Psychological Measurement · doi:10.1177/001316446802800203 · Cited by 70
Estimation of Reliability and True Score Variance from a Split of a Test into Three Arbitrary Parts
Kristof, W. (1974) · Psychometrika · doi:10.1007/bf02291670 · Cited by 55
The Definition and Estimation of Test Reliability
Cureton, E. E. (1958) · Educational and Psychological Measurement · doi:10.1177/001316445801800404 · Cited by 42
Some Hypotheses Concerning test Adequacy
Fiske, D. W. (1966) · Educational and Psychological Measurement · doi:10.1177/001316446602600107 · Cited by 38
A proposed procedure for increasing the efficiency of objective tests.
Flanagan, J. C. (1937) · Journal of Educational Psychology · doi:10.1037/h0057430 · Cited by 31
Language, time, and person effects on attitude scale translations.
Katerberg, R., SMITH, F. J., & Hoy, S. (1977) · Journal of Applied Psychology · doi:10.1037/0021-9010.62.4.385 · Cited by 30
THE RELIABILITY OF SPEEDED TESTS
Gulliksen, H. O. (1950) · ETS Research Bulletin Series · doi:10.1002/j.2333-8504.1950.tb00876.x · Cited by 29
The Relationship between Factorial Composition of Test Items and Measures of Test Reliability
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Cited by
Sorted by citations
Making sense of cronbach’s alpha.
Tavakol, M., & Dennick, R. (2011) · International Journal of Medical Education · doi:10.5116/ijme.4dfb.8dfd · Cited by 15,126
The Use of Cronbach’s Alpha When Developing and Reporting Research Instruments in Science Education
Taber, K. S. (2018) · Research in Science Education · doi:10.1007/s11165-016-9602-2 · Cited by 10,679
“Cronbach ’ s alpha has been described as ‘ one of the most important and pervasive statistics in research involving test construction and use ’ (Cortina, 1993, p. 98) to the extent that its use in research with multiple-item measurements is considered routine (Schmitt, 1996, p. 350).”
BackgroundInfluentialConstructing validity: Basic issues in objective scale development.
Clark, L. A., & Watson, D. (1995) · Psychological Assessment · doi:10.1037/1040-3590.7.3.309 · Cited by 6,567
Mokkink, L. B., Terwee, C. B., Patrick, D. L., Alonso, J., Stratford, P. W., Knol, D. L., Bouter, L. M., & de Vet, H. C. W. (2010) · Journal of Clinical Epidemiology · doi:10.1016/j.jclinepi.2010.02.006 · Cited by 4,465
“According to these sources, homogeneity of the items refers to the unidimensionality of a scale [11] and is a prerequisite for a clear interpretation of the internal consistency statistic [8,11].”
BackgroundMethodInfluentialHandbook on Constructing Composite Indicators: Methodology and User Guide
OECD, Union, E., & Joint Research Centre - European Commission (2008) · doi:10.1787/9789264043466-en · Cited by 3,960
Metadata
- Authors
- Cortina, J. M.
- Venue
- Journal of Applied Psychology
- Published
- 1993-02
- Volume
- 78
- Issue
- 1
- Pages
- 98-104
- ISSN
- 0021-9010 (ISSN-L)
- 1939-1854
- OpenAlex
- W2117012826
- Cited by
- 8,810
- References
- 26
- Citations by year
- 2026: 523 · 2025: 499 · 2024: 518 · 2023: 606 · 2022: 639 · 2021: 685 · 2020: 589 · 2019: 474 · 2018: 407 · 2017: 411 · 2016: 418 · 2015: 428 · 2014: 437 · 2013: 372 · 2012: 309
- FWCI
- 29.15
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- Journal of Applied Psychology (publishedVersion)
- Topics
- Social Sciences › Decision Sciences › Management Science and Operations Research › Psychometric Methodologies and Testing
- Social Sciences › Decision Sciences › Statistics, Probability and Uncertainty › Reliability and Agreement in Measurement
- Social Sciences › Psychology › Applied Psychology › Psychological Testing and Assessment
- Keywords
- Cronbach's alpha, internal consistency, reliability theory, scale development, test length, dimensionality
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