Identifying a well-defined research question is the first step for writing a literature review. It should focus on something from the research field that needs to be explored, where there are gaps in the information. This will ensure that your contribution is valuable and that you are providing readers with a different angle or perspective on an issue or problem.
Your topic needs to be given careful consideration. A research question like “why are social networking sites harmful?” is too broad; there will be too much information to write a concise literature review. Change it to “how are online users experiencing or addressing privacy issues on Twitter and Facebook?" and it is more specific. It gives you a niche within the research field to focus on and explore.
Limiting the scope
Sometimes a broad topic can be narrowed by using one or more extra criteria, which can include:
methodology (e.g., qualitative or quantitative, fieldwork/ethnography)
Mindfulness therapeutic intervention in aiding smoking cessation
Social media in college and university
Use of Instagram and Twitter in university classrooms for educational purposes
Effect on the environment from global warming
Effect of glacial melting on penguins in Antarctica