Difference between revisions of "Cronbach's Alpha Values"

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''contributed by Frank LaBanca, EdD''
 
''contributed by Frank LaBanca, EdD''
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Cronbach's alpha measures internal consistency, meaning how much the items on a scale actually measure the same dimension. For example, when considering instrumentation for quantitative research, part of assessing a reliable instrument would include reviewing the Cronbach's alpha values for the scales. An example of this is reported below, for the School Attitudes Assessment Survey - Revised (SAAS-R):
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As reported by McCoach and Siegle (2003), the scores demonstrated a classical theory internal consistency reliability coefficient of at least .85 on each of the five factors.
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McCoach, D. B., & Siegle, D. (2003). The school attitude assessment survey – revised: A new instrument to identify academically able
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    students who underachieve. ''Educational and Psychological Measurement, 63''(3), 414-429. DOI: 10.1177/0013164402251057.
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"contributed by Lauren Moyer"

Revision as of 09:22, 13 December 2019

Internal consistency

Cronbach's Alpha Internal Consistency
0.9 ≤ α Excellent
0.8 ≤ α < 0.9 Good
0.7 ≤ α < 0.8 Adequate
0.6 ≤ α < 0.7 Questionable

contributed by Frank LaBanca, EdD


Cronbach's alpha measures internal consistency, meaning how much the items on a scale actually measure the same dimension. For example, when considering instrumentation for quantitative research, part of assessing a reliable instrument would include reviewing the Cronbach's alpha values for the scales. An example of this is reported below, for the School Attitudes Assessment Survey - Revised (SAAS-R): As reported by McCoach and Siegle (2003), the scores demonstrated a classical theory internal consistency reliability coefficient of at least .85 on each of the five factors.

McCoach, D. B., & Siegle, D. (2003). The school attitude assessment survey – revised: A new instrument to identify academically able

    students who underachieve. Educational and Psychological Measurement, 63(3), 414-429. DOI: 10.1177/0013164402251057.

"contributed by Lauren Moyer"