Having a framework for your research question can help identify key concepts of your research and facilitate the process of document selection.
The 5 Ws are questions whose answers are considered the basis of information-gathering:
Mind mapping your research question framework enables you to visualise the relationships between concepts and information, teasing out themes and keywords.
Identify and keep a record of keywords, terms and phrases expressing your research question. Find synonyms, alternative words. Translate them if necessary, since the language in which you search will influence the results.