Criteria for a problem formulation
Is my idea novel?
If you have an idea for a research topic, you should check to see if anyone else has already researched the same topic before you embark on your own research. Google Scholar is a good resource to use for this purpose. Try to find the most specific words for your topic and enter them into the search field. For example if you are interested in researching the smoking habits of immigrants in Israel, you could enter smoking immigrants Israel in the search field and see if you discover any papers that resemble what you are thinking about researching. You would for example find the following paper:
Baron-Epel, Orna, et al. “Multiethnic differences in smoking in Israel. Pooled analysis from three national surveys.” The European Journal of Public Health 14.4 (2004): 384-389.
You could then consider if this article focuses on what you would like to research or if your topic is different from the research already done. If the research is similar to your proposed topic, you can also see which other researchers have based their research on this article by clicking on the “Cited by” link under the article. By looking at these articles you might be inspired to find a new topic or a new angle on the topic.
If you don’t find any articles that are very similar to your planned topic, then you probably have a novel idea. But the fact that your idea is novel doesn’t necessarily mean that it is a good idea. There may be good reasons that nobody has studied the topic before, for example that the subject is irrelevant.
Is my idea relevant?
Besides being novel, you must also have a clear feeling that your topic or your angle on your topic is relevant for anyone other than yourself as a student. Clarify this by using your explorative literature search to describe the specific problem – geographic, scope, extension – and to establish to yourself that your topic ties up with the nature of the problem, even if it is not measurable at this time. This work will hopefully bring you closer to a concrete description and argument of the aim of the thesis and why it is worth dealing with.
But is it feasible too?
Is my question feasible?
Once you have an idea for your research topic that appears to be novel and relevant, you should then consider whether it is feasible. E.g. will you be able to perform the research and write your thesis before its deadline? Time is quite short to finish your thesis and if your thesis will be based on empirical research there can be a lot of different practical considerations to deal with. Therefore, think carefully about how long time it will take to collect and process data, e.g. from interviews; whether you have the needed contacts to realize it, whether your project is ethically justifiable and whether you have the necessary financial resources to cover the costs. The explorative literature search may give you an idea of the scope and nature of the work that you will be expected to do.
Identify some good narrow keywords for the problem you want to work with and check in Google Scholar what has been published on this subject. Select better keywords based on the result.