An internal arts school is different to a night school course or a keep fit class.
Its mandate is far broader.
With a keep fit class you can attend intermittently, and train as much or as little as you like.
It makes no real difference.
The student is just a number in the register.
With a tai chi school you are expected to have a different attitude.
There is a detailed syllabus offering a clear pathway of progression, and a specific code of conduct.
Students are asked to train between classes and attend regularly.
Individual progress is monitored and supervised by the instructor.