I'm at the point in my graduate career where I must select an advisor within the coming months. I have about 4 professors narrowed down based on research interests and experience. One professor I get along with very well, but believe our academic interests are not exactly aligned. Another has more similar research interests but our personalities are not the best match. I am trying to think of ways to narrow down my selection. What "tests" should I try on potential advisors to help guide me in a selection. Note: by tests I don't mean literal exams. That would be absurd. Think of a test as a clever question, body language, reaction to a situation, etc.