What is their experience in years of teaching or instructing?

It’s a great idea to ask for the Karate instructor’s experience in years of teaching and instruction for two reasons:

1. After two or three decades, they should have accumulated considerable knowledge over that time.

2. If they have been teaching for a long time, it shows they have been consistently helping others and that their students have stayed with them because they like the instructor/s. They wouldn’t hang around them for long unless there is some good benefit to the student.