[Performing content validation process in development of questionnaires]

ABSTRACT

Content validity is the first type of validity that has to be ensured during the design of a tool. Its prerequisite for other validities and its close relationship with the tool reliability place it in a vital position in the questionnaire design. However, since it has not been paid enough attention in national publications therefore in this paper we will explain the different steps in preparing an appropriate content for questionnaires and also their assessment. The steps of the content validation process for designing valid and reliable questionnaires have been explained in this paper development [domain identification, items generation and instrument construction], Judgment - quantification [determining the inter rater agreement among experts, determining the clarity and relevancy of each of the questions along with the clarity, relevancy and comprehensiveness of the tool as a whole] have been explained. The benefits of performing the content validation in questionnaire development are not increasing the possibility of accessing desirable content validity indexes [relevancy, clarity, and comprehensiveness] only, but also improving the Reliability indexes of tool and decreasing need for resources [financial and temporal] are the other benefits of this approach. Although subjective nature of experts' responses is the problematic issue in this process but the more quantitative steps of the content validation has reduced considerable part of previous worries about this process. These issues explain why content validation has become a suitable process for questionnaire