Students will usually start to work towards their thesis by the mid of their second year, and they will fully concentrate on it as of the beginning of their third year. The process of determining the final thesis topic is always an individual one, and it involves an intense co-ordination process between the candidate and the supervisor. Thus, it is impossible to determine the exact research question at the time when students enroll in the PhD program. That being said, candidates should expect that their topic will fall square into the overall research agenda of the subject area. For more details, see

For general information on the PhD Thesis, you can consult