Designing and Evaluating Validity and Reliability of the Questionnaire of Factors Affecting Consumer's Choice of Type of Dairy Based on the Reasoned Action Theory

Despite the fact that pasteurization of raw milk increases the quality and health of dairy products, many people tend to consume raw milk and its products. The purpose of the current study was to design a questionnaire to determine the factors affecting choosing the type of dairy based on the reasoned action theory.
This descriptive study was conducted on the patients referred to Dr. Shadpour Health Care Center from September to October in 2017. The questionnaire was designed via literature review, focus group discussions, and interview with experts. A total of 14 specialists were selected to determine the content validity scores and 15 subjects referred to Dr. Shadpour Health Care Center were used to determine the reliability of the questionnaire. Finally, content validity index (CVI) and content validity ratio (CVR) were calculated by using Cronbach’s alpha and intraclass correlation coefficient (ICC) in SPSS, version 23.00.
The first questionnaire consisted of 101 questions and after evaluation of validity and reliability, 32 questions were obtained. The content validity index of the questionnaire was 0.88, the content validity ratio 0.68, the Cronbach's alpha coefficient 0.83, and the internal correlation coefficient (ICC) 0.80 with the confidence interval of (0.58-0.93).
Considering the findings, it seems that the present questionnaire has acceptable reliability and validity. Therefore, it can be used as a useful tool in determining the factors affecting choosing the type of dairy by consumers.