The study session that takes place the morning of the test is for EVERYBODY. This is MANDATORY to be able to take the written test that afternoon. You study a booklet that has information pertaining to the written test. (Memory Retention)
The study sessions being given prior to test day are voluntary and go over general test material. It just gives people an idea of what to expect on test day and the material involved. Arrive early on test day because once the doors are closed, no one will be allowed in for any reason.