When to start contacting potential supervisors? I'm a computer science master student, and I'm planning to graduate in spring 2022.  In  Finland, doctoral programs specifically state that applicants need to find a supervisor before applying. The supervisor has be be willing to mentor the applicant, and the research proposal, which is submitted with the application, also has be approved by the supervisor. I know that writing a decent research proposal takes a significant amount of time, which is why I have to get in touch with prospective supervisors well in advance. The question is when? My studies are approximately 30% completed, by the end of this academic year I will be done with everything except for my thesis. I don't have any solid idea about my future thesis yet. However, I have certain academic interests in machine learning and robotics.
Should I wait until I know the topic of my master's thesis next fall? Or should I start contacting doctoral programs next spring? The messy thing is that some universities have rolling admissions, while others have application periods once or twice a year. I have also been hopeful that by contacting professors at home university I could get to write a master's thesis connected to their research, would it be appropriate to ask them about such opportunities? I have taken several courses with some of them but I'm unsure they remember me since we normally have anywhere from 50 to 100 students in each course.
I’ve supervised Masters for 20 years, and my advice is to think about what really interests you, not just these disciplines, but to think how they can be used. That list may include solutions to observed or perceived problems, it may also include blue sky research. The thing is, firstly, you don’t need a Masters to do a PhD, though if you do have one, it might make sense to follow up on your Masters thesis. Having a chat with a good supervisor with no commitment may offer you insight into what you want to do.
Secondly, you should think about your endpoint. Do you want to stay in acadaemia or are you looking for a commercial outcome? I worked at one of the top places for applied research. This particular University was solely postgraduate and focused purely on commercial outcomes having a worldwide reputation for its research and its students, and its contribution to the world. For example, the mirrors for the James Webb Space Telescope (the Hubble replacement) were made in its precision laboratories.
If you are looking at becoming an academic, then that will determine which type of university you might apply to. If you are looking to create a foundation for a career, you must also select wisely. My advice would be to decide which it is academic or commercial outcome. A piece of further advice would be that if you’re a practical person, you should be involved with an applied research institution rather than the purely academic type.
Lastly, research proposals are exactly that. They are only what you propose....what you’d like to do. They rarely match up to the finished thesis. Research is a living animal. It evolves, it changes, it matches its environment. The beauty of real world research is that you can point to something and say “I did that”. It’s your legacy to the World. You will go down many routes when you start to research. You will be faced with dead ends, you will have to re-trace your steps. So don’t get hung up on the proposal. A good supervisor will allow the exploration and nudge you gently in the right direction.
See which Universities are active in your specific interests. Then, check which supervisors have a track record in what you’re interested in. The supervision process is no different whether you’re doing astrophysics, chemistry, engineering or English. Methodologies and methods vary, but a good supervisor will always demand rigour. Good luck.