I'm applying to a coursework + thesis masters programme and am wondering how specific do I have to be when mentioning my research interests in my email to a potential advisor. I have applied to another programme before and I think I was too specific when I spoke to the prof. He rejected me immediately because he thinks that our interests do not fit.
As an undergrad applying into a masters course, do I also need to have a research topic ready when contacting the prof? I have trouble refining my research topic as I'm applying into a specialization I've no experience in.
I understand that especially for coursework, there is a chance that our research interest (or topic) might change over time, and in some schools/faculty, masters students aren't really given the full autonomy to decide on their research topics.
How can I convince the prof without sounding like I'm trying to fit into the lab's interests or without deviating too much from his interests?