Questions, Answers and Evidence

I just saw that Moore's Principia Ethica is online. It has a great beginning, relevant to all writers and researchers, in many fields:

Preface.

"It appears to me that in Ethics, as in all other philosophical studies, the difficulties and disagreements, of which its history is full, are mainly due to a very simple cause: namely to the attempt to answer questions, without first discovering precisely what question it is which you desire to answer."

Figuring out what exact question(s) about a topic one is trying to answer determines how one will answer those questions and what types of evidence is needed to answer those questions. 

Thanks, G.E.!