In this scenario, the student is a passive participant in the process. The information learned is impersonal. Clearly, the teacher is in control of the learning process; his or her interests dictate what and how fast the students learn.
The answer in all three cases is that rudder is used to help maintain stability in the roll. A little rudder at just the right time can help keep the nose up in a slow roll or even an aileron roll, as the plane rotates through the sideways portions of the roll when gravity is otherwise not countered.
Using Mr. Stokoe's method, a rudder that was 1/60th of the hull area would be 481.75ft2 and 1/70th would be 412.43ft2 . Using the method in the SNAME book, a rudder that was 2% of the hull area would be 577.4 ft2 ;1.5% would be 433.1ft2. So Titanic's rudder would be very slightly too small.