Answer: Provide specific information about the schools of the time period
Step-by-step explanation:
By stating where the classes were normally held as being in the private houses of the teachers, the text aims to show the location/ setting of the schools which is a specific detail about the schools of the time.
It is akin to saying that science experiments in schools today are usually conducted in specialized school laboratories. The school laboratories in the text is a specific detail about science classes today.