How many of us have looked at our ratio of personnel on the scoreboard and wondered if there was a way to accelerate the advancement of students? If you are willing to accept a few uneducated people and you need a quick injection of labour, fire the teacher. He plus all the students immediately go to the labour pool.
This is not very nice, but there are times when the need for workers overrides the need for smart workers. You can restore the teacher immediately, and start up a new batch of students from the pool of children.
Since nomads show up randomly, waiting for them to show may be too late, and there may be more than you are willing to absorb at that moment.
This would have come in useful a few days ago for
@kee's Fast-Forward Challenge -- I really could have used the teacher and two students. I get so focused on getting that first crop of educated laborers out of school that it never occurs to me to close the school when I need labor.
I don't recall offhand at what age children become laborers when there's no school, and when they enter school if there is one. If there's a difference, closing a school might not give you the youngest students as laborers immediately. With more than one school, there may be a decision to be made about which one to close to get the most immediate benefit.
When they turn ten, children either enter school or become uneducated laborers.