Small Groups require advance preparation. Each Small Group session will be preceded by a lecture introducing the relevant topic. This means that you will always have to keep up, but preparation for exams will be easier. PBL starts with part of a case description. You define the patient's problems as you go along and decide what information you need.
Tutors provide more history, physical exam findings, labs, etc.
IF you ask. You will obtain additional information from texts, faculty, the internet, etc. to solve the case at the next session. Students have said that they learn better when they are more involved, and you will be solving medical problems this way for the rest of your professional lives. Patients' health changes over time and the cases will evolve too. The cases illustrate major problems that you will encounter no matter what branch of medicine you choose.