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A Review on Sample Size Determination for Cronbach’s Alpha Test: A Simple Guide for Researchers
BACKGROUND: Reliability studies are commonly used in questionnaire development studies and questionnaire validation studies. This study reviews the sample size guideline for Cronbach’s alpha test. METHODS: Manual sample size calculation using Microsoft Excel software and sample size tables were tabu...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Penerbit Universiti Sains Malaysia
2018
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6422571/ https://www.ncbi.nlm.nih.gov/pubmed/30914882 http://dx.doi.org/10.21315/mjms2018.25.6.9 |
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author | Bujang, Mohamad Adam Omar, Evi Diana Baharum, Nur Akmal |
author_facet | Bujang, Mohamad Adam Omar, Evi Diana Baharum, Nur Akmal |
author_sort | Bujang, Mohamad Adam |
collection | PubMed |
description | BACKGROUND: Reliability studies are commonly used in questionnaire development studies and questionnaire validation studies. This study reviews the sample size guideline for Cronbach’s alpha test. METHODS: Manual sample size calculation using Microsoft Excel software and sample size tables were tabulated based on a single coefficient alpha and the comparison of two coefficients alpha. RESULTS: For a single coefficient alpha test, the approach by assuming the Cronbach’s alpha coefficient equals to zero in the null hypothesis will yield a smaller sample size of less than 30 to achieve a minimum desired effect size of 0.7. However, setting the coefficient of Cronbach’s alpha larger than zero in the null hypothesis could be necessary and this will yield larger sample size. For comparison of two coefficients of Cronbach’s alpha, a larger sample size is needed when testing for smaller effect sizes. CONCLUSIONS: In the assessment of the internal consistency of an instrument, the present study proposed the Cronbach’s alpha’s coefficient to be set at 0.5 in the null hypothesis and hence larger sample size is needed. For comparison of two coefficients’ of Cronbach’s alpha, justification is needed whether testing for extremely low and extremely large effect sizes are scientifically necessary. |
format | Online Article Text |
id | pubmed-6422571 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | Penerbit Universiti Sains Malaysia |
record_format | MEDLINE/PubMed |
spelling | pubmed-64225712019-03-26 A Review on Sample Size Determination for Cronbach’s Alpha Test: A Simple Guide for Researchers Bujang, Mohamad Adam Omar, Evi Diana Baharum, Nur Akmal Malays J Med Sci Original Article BACKGROUND: Reliability studies are commonly used in questionnaire development studies and questionnaire validation studies. This study reviews the sample size guideline for Cronbach’s alpha test. METHODS: Manual sample size calculation using Microsoft Excel software and sample size tables were tabulated based on a single coefficient alpha and the comparison of two coefficients alpha. RESULTS: For a single coefficient alpha test, the approach by assuming the Cronbach’s alpha coefficient equals to zero in the null hypothesis will yield a smaller sample size of less than 30 to achieve a minimum desired effect size of 0.7. However, setting the coefficient of Cronbach’s alpha larger than zero in the null hypothesis could be necessary and this will yield larger sample size. For comparison of two coefficients of Cronbach’s alpha, a larger sample size is needed when testing for smaller effect sizes. CONCLUSIONS: In the assessment of the internal consistency of an instrument, the present study proposed the Cronbach’s alpha’s coefficient to be set at 0.5 in the null hypothesis and hence larger sample size is needed. For comparison of two coefficients’ of Cronbach’s alpha, justification is needed whether testing for extremely low and extremely large effect sizes are scientifically necessary. Penerbit Universiti Sains Malaysia 2018-11 2018-12-28 /pmc/articles/PMC6422571/ /pubmed/30914882 http://dx.doi.org/10.21315/mjms2018.25.6.9 Text en © Penerbit Universiti Sains Malaysia, 2018 This work is licensed under the terms of the Creative Commons Attribution (CC BY) (http://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Original Article Bujang, Mohamad Adam Omar, Evi Diana Baharum, Nur Akmal A Review on Sample Size Determination for Cronbach’s Alpha Test: A Simple Guide for Researchers |
title | A Review on Sample Size Determination for Cronbach’s Alpha Test: A Simple Guide for Researchers |
title_full | A Review on Sample Size Determination for Cronbach’s Alpha Test: A Simple Guide for Researchers |
title_fullStr | A Review on Sample Size Determination for Cronbach’s Alpha Test: A Simple Guide for Researchers |
title_full_unstemmed | A Review on Sample Size Determination for Cronbach’s Alpha Test: A Simple Guide for Researchers |
title_short | A Review on Sample Size Determination for Cronbach’s Alpha Test: A Simple Guide for Researchers |
title_sort | review on sample size determination for cronbach’s alpha test: a simple guide for researchers |
topic | Original Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6422571/ https://www.ncbi.nlm.nih.gov/pubmed/30914882 http://dx.doi.org/10.21315/mjms2018.25.6.9 |
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