When trying to decide which scientific method to use when exploring a question, what is the best rule of thumb to go by? We live in a very complex world just filled with economic and social...

When trying to decide which scientific method to use when exploring a question, what is the best rule of thumb to go by?

We live in a very complex world just filled with economic and social challenges. How can the research process help us solve or better understand some of those problems and issues?