Each year, starting in the fall quarter of your second year, you will meet with your thesis committee. Usually, this committee consists of 3-4 faculty members selected by you. See your Home Program's handbook for specific details about the composition of your committee.
Your first committee meeting formally serves as your qualifying exam. This is a great opportunity to work out research ideas and to receive feedback on your scientific reasoning. See your Home Program's handbook for the specific format of your qualifying exam, and read advice from students on having a successful first committee meeting.
After your first meeting, you should (and are required to) meet with your committee yearly. Use these meetings to take a step back from day-to-day research, discuss your ideas, and receive feedback. Don't be intimidated by these meetings! Stanford faculty want to help you succeed, and the nature of these meetings is collegial. Read advice from students on how to prepare for your committee meetings and to make sure you get the advice you need