Checking the content validity of measuring instruments

Closely related to the validity of the results of a survey is the reliability and validity of the measuring instrument used, because if the measuring instrument does not provide a satisfactory level of these two criteria, it cannot or should not be used in a research. In the context of this article, we will discuss in detail the process of evaluating the content validity of a measuring instrument in order to establish to what extent it conceptually covers the range of the variable(s) intended to measure. For this purpose, we will use the most commonly used method among researchers based on the agreement between the judges, which is the Content Validity Index (CVI) and we will describe step by step the whole process, from the selection of the judges to the final calculation of the index using for this purpose the most common and available to all Microsoft Excel spreadsheet software.