Choosing dissertation titles can be done in many ways. The easiest way to go about it is to choose a subject you are comfortable with and then proceed to gather a list of topics you think you could write about. At first, it would help if you gather your thoughts about which general topic would serve best in increasing your knowledge about the subject and then proceed with zeroing in on the exact title.
If you have been given the general topic, you would be bound by limitations. In this case, you could write down the related sub topics. Any sub topic that comes to your mind at that time is good enough. It would be possible to go ahead with vague ideas. It is important though that you list these out in the order of hierarchy that you would prefer.
