It's a significantly different way to operate than being the sole teacher of a class. (teachermagazine.com.au)
So, for example in a primary school it might be a scientist coming in, or an artist in residence, who's teaching with the regular teacher of the class. (teachermagazine.com.au)
Ross Snyder has said, «No person has earned the right to be pastor of a church or teacher of a class until he has risked himself with his people.» (religion-online.org)