Abstract
This article is a continuation of the previous module on designing questionnaires and clinical record form in which we have discussed some basic points about designing the questionnaire and clinical record forms. In this section, we will discuss the reliability and validity of questionnaires. The different types of validity are face validity, content validity, criterion validity, and construct validity. The different types of reliability are test-retest reliability, inter-rater reliability, and intra-rater reliability. Some of these parameters are assessed by subject area experts. However, statistical tests should be used for evaluation of other parameters. Once the questionnaire has been designed, the researcher should pilot test the questionnaire. The items in the questionnaire should be changed based on the feedback from the pilot study participants and the researcher's experience. After the basic structure of the questionnaire has been finalized, the researcher should assess the validity and reliability of the questionnaire or the scale. If an existing standard questionnaire is translated in the local language, the researcher should assess the reliability and validity of the translated questionnaire, and these values should be presented in the manuscript. The decision to use a self- or interviewer-administered, paper- or computer-based questionnaire depends on the nature of the questions, literacy levels of the target population, and resources.