A passenger seat assembly convertible between a two-seat configuration and a three-seat configuration, and including a seat assembly base and first, second and third seats for carrying respective seat bottom and seat back cushions, the first and third seats defining outboard seats and the second seat defining a center seat. The lockable caster wheels are adapted to be locked for a trailing mode of operation and a backing mode of operation. A channel within the flat base houses a threaded shaft. When the regular channels are all full, then regular priority calls are connected as low priority calls or not at all. System embodiments are also provided that incorporate the functions of the methods for tutoring a student.