A research question refers to a more focused question addressing a single concept of a hypothesis while a hypothesis is utilized in stating the relationship that exists between two variables (Salkind, 2010). Research questions are basically questions derived from the hypothesis, they are more general. However, hypothesis is basically statement by the researcher that speculates an outcome. The hypothesis is tested empirically with statistical tools and largely used in quantitative research. A research question is essentially an issue which you want to address through your research (Trochim & Donnelly, 2001). To address the research question, you derive hypothesis. It may be one or more for a research question depending upon the research. The hypothesis is a statistical statement, which can be tested through statistical method. However, it is not always true that all research questions must have and hypothesis.
In exploratory research as you try to assess items that are not covered before, so you may go for research questions. When you move towards descriptive research you may use either questions or hypotheses, and in causal research you also go for both with more quantitative tools (Salkind, 2010). All through this process you need to be sure about what your objectives are in doing the research. Research questions should be answerable and the hypothesis should be testable as a complementary to your research question’s answer, you can have them both or either one. But, should bear in mind, that, hypothesis directly derive from your research questions whereas proposition derive from a theoretical(Trochim & Donnelly, 2001). When it comes to deductive research whereby researchers utilizing logic and scientific findings to prove assumptions, hypothesis is preferred over the research question.