Have you visualised your subject well? Next, formulate a global main question. Your main question forms your starting point. This question describes exactly what you want to know and gives direction to your search process. It is therefore important to formulate this question well.
Your main question must be straightforward, with clear concepts.
Your main question must be specific to be able to search specifically.
Your main question must be relevant to contribute to the writing of your article, your objective.
Your main question must be formulated openly, so not a question with a "yes" or "no" answer.
Your main question must be realistic, you can find the answer within an acceptable time frame and with sufficient resources. At the same time, the question must also be 'research-worthy'; the answer must add something
Tips: If you start a question with 'what', 'how' or 'which' you automatically have an open question. Do not start the question with 'why', why-questions are often not specific enough.