I recommend

The SAGE Handbook of Qualitative Research (2017)

Norman K. Denzin, Yvonna S. Lincoln

For Grounded Theory you would usually start with a broad research question and then narrow it down as you learn more about the topic. For example, “What is the nature of the relationship between...?”

many thanks for your valuable insights.

my broad research question is:

what is the process of conflict between mother-in-law and daughter-in-law from the perspective of the daughter-in-law.

It's important to keep in mind that most qualitative research is inductive, that is, it does not begin with hypotheses or theoretical positions, rather it begins "with the data themselves, from which theoretical categories and relational propositions may be arrived at by inductive reasoning" (Lincoln & Guba, 1985, p. 333). In this way, qualitative research is often said to have an emergent design (Merriam & Tisdell, 2016). The emergent nature of qualitative research allows for study designs to change as they are being implemented (Hatch, 2002). This, of course, has always been one of the prominent criticisms of qualitative research and, as such, requires that we take additional measures to monitor our subjectivities throughout the process, and to keep an audit trail (Guba & Lincoln, 1982).

In terms of research questions, these, too, can be emergent. In fact, you may not settle on a final research question until something jumps out of your data toward the very end of your analysis. At any rate, you've begun with an idea of the phenomenon that you wish to study, and your final RQs will become much more apparent as you begin to really see the secrets that your data unlock.

The idea that one begins without any theory or other preconceptions is often referred to as a "tabla rosa" or "blank slate" position. This argument is now widely discarded in qualitative research, since everyone begins with assumptions about how the world works and what is important to study.

The preferred alternative is to be as explicit as possible about one's initial position, and to be reflexive about the influence that one's perspective has at every stage in the research process, including the formulation of research questions. Unfortunately, the advice about how to accomplish this reflexivity is often rather vague. In particular, the main suggestion offered is usually to keep a journal, so that you are continually aware of the influences on your thinking. I personally wish there were more recommendations for concrete techniques to accomplish reflexivity.

Amazing guidelines. Thanks, Dr. Morgan and Evans for your valuable comments. I was much more clear now. It seems to me now that my questions may become clearer as the research proceeds. It is difficult to endure the ambiguity since I am a novice in the qualitative method.

I would start by defining the "conflict".