A focus on reliability in developmental research through Cronbach’s Alpha among medical, dental and paramedical professionals

Abstract

Background: The purpose of this paper is to demonstrate the quantitative methods used to determine reliability in developmental research. Author represented methods of reliability and emphasizing the technique and conditions for reliability through Cronbach’s Alpha that have been utilized in medical, dental and paramedical education. Materials and Methods: Validity and reliability of a questionnaire are the basic elements in the development of a
measurement instrument. Reliability may be calculated in a number of ways but Cronbach's alpha is widely used measure of internal consistency or reliability of a survey instrument. Calculating alpha has become common practice in medical, dental and paramedical education research when dichotomous and multiple-item measures of a concept are applied. Results: Cronbach Alpha can be employed significantly for both binary-type and large-scale data to
judge the reliability of the instrument. The study demonstrated the technique of interpreting the reliability by using Chronbach’s alpha for one domain of the questionnaire administered among 60 samples was developed by Elango. Cronbach's alpha demonstrates the internal consistency based on average correlation or the co-variances of items in a survey instrument or development of a questionnaire. Unstandardized alpha is based on the covariance matrix while the standardized alpha based on the correlation matrix. Overall, alpha is the most appropriate measure of reliability when the items measure different substantive areas within a single construct. Conclusion: This article spread awareness and offers an understanding of use of Chronback’s alpha and basic guidelines in reporting the reliability of a survey instrument (questionnaire) in development research studies accurately and scientifically so that the instrument get validation for its use in future.