The earlier you are in your career the more difficult you might find it to land on a research question, just because there is so much to choose from.
You can find inspiration in many places:
One way to think about getting from anything in the world down to a specific research question is:
Topic - A general area of interest
Problem - A problem, gap, or controversy in your Topic
Question - The question about the problem, gap or controversy that you would like to answer
Once you have gotten from a topic to a question, you need to make it specific enough to both be able to answer it, and to be able to explain to other people why it matters.
For clinical types of questions, PICO is used to plan a question that is specific enough to search in a database, but it can also help you to focus in on who/what you are studying:
|P||Population, problem||Who or what are you studying? Age groups, health conditions, etc. of relevance go here|
|I||Intervention||What treatment, procedure or test are you studying?|
|C||Comparison||Are you comparing either the Intervention or the Population to another intervention or population?|
|O||Outcome||What outcomes are you interested in?|
If PICO doesn't fit, for any study about an effect you can use "Who Does what To whom To what effect":
|Who||Population who acts|
|To Whom||Objects of action|
|To What Effect||Outcome of action|
You need to be familiar with the existing literature to be sure that the question you want to ask and the way you want to investigate it will contribute something valuable. These approaches can help:
Aslam S, Emmanuel P. Formulating a researchable question: A critical step for facilitating good clinical research. Indian journal of sexually transmitted diseases and AIDS. 2010;31(1):47.
Beckman LM, Earthman CP. Developing the Research Question and Study Design. Support Line [Internet]. 2010;32(1):3.
Farrugia P, BScN, Petrisor, Bradley A., MSc, MD, Farrokhyar, Forough, MPhil, PhD, Bhandari, Mohit, MD, MSc. Research questions, hypotheses and objectives. Canadian Journal of Surgery. 2010;53(4):278-81.
Lipowski EE. Developing great research questions. American Journal of Health-System Pharmacy. 2008;65(17):1667-70.
Morrison J. Developing research questions in medical education: the science and the art. Medical Education. 2002;36(7):596-7.
When you have a research question in mind, consider these aspects to help you decide if it is both do-able and worth doing:
Adapted from "Characteristics of a Good Research Question" "Feasible, Interesting, Novel, Ethical and Relevant (which form the mnemonic FINER)":
Conceiving the Research Question and Developing the Study Plan. Designing Clinical Research. 2013:14-22. (Chapter 2)