Abstract
The selection of instruments that will be used to collect data is a crucial step in the research process. Validity and reliability of the collected data and, above all, their potential comparability with data from previous investigations must be prioritized during this phase. We present a decision tree, which is intended to guide the selection of the instruments employed in research projects. Studies conducted along these lines have greater potential to broaden the knowledge on the studied subject and contribute to addressing truly socially relevant needs.