Research is a form of problem solving, and the first step in problem solving is to identify the problem. In other words, what question do you hope to answer with your research?
A research question is a clear, focused, specific, complex, arguable question around which you focus your research. It should be a question in which you are genuinely interested in finding an answer!
Unclear: Why are social networking sites harmful?
Clear: How are online users experiencing or addressing privacy issues on Facebook?
The unclear version of this research question doesn't specify which social networking sites or what kind of harm is being done. The clearer version names a specific social networking site, the type of harm (privacy issues), and whom the issue is harming (users). A strong research question does not leave room for ambiguity or interpretation.
Unfocused: What is the effect on the environment from Global Warming?
Focused: How is glacial melting affecting Penguins in the Arctic Circle?
The unfocused version is much too broad and could not adequately be answered in a book, let alone a college-level research paper. The focused version narrows down the specific cause (glacial melting), the location (Arctic Circle), and the affected population (penguins).
Here are some strategies for generating a good research question: