The answer for the previous post is 4. Less than Several Minutes for observing. Then I can know your estimate level of skill.
To be honest, if I would confess clearly I wouldn't need several minutes. I could understand Intuitively just within several seconds from starting observation.
"She would be very skillful."
"He seems like a little bit worse..."
These my intuition was almost true.
If I guess this teacher was good, so his lesson would keep good until the last part of the lesson.
On the other hand, if I guess this teacher was not good, so his lesson would just keep bad until the last part of the lesson.