Maybe in later grades it's helpful, I don't think it requires a phd to teach 8 year olds multiplication tables. Private school, as far as i can tell, have 18 kids with an aide per classroom. Public school will have 30-40 kids per class.
I dunno. if it was easy it wouldn't be a problem. There are lots of dials to turn. As you say, qualification levels of teachers is is one, frequency of testing is another. I think the least effort improvement is just smaller classes.
The very highest pupil to teacher ratio seems to be California with under 25. The average seems to be 16. [1]
From personal experience, my child goes to a public school and his classroom is about 25 students with a teacher and 2 assistant teachers, around 8 kids per. instructor.
There seems to be differing research on class size anyway, with even the most liberal interpretation of results pointing to smaller class sizes only helping "troubled" children. Also, most of the countries that have larger average class sizes than the US do better than us in rankings.[2] The definition of "troubled" seems to range from poor to lower IQ.
The US seems to do about as well as Latvia and Russia in education, and not much higher than Mexico, Turkey, and Thailand, despite spending more on education per student than nearly anyone else in the world. I wonder if we might just study (with an open mind) what other countries are doing and incorporate those findings, rather than guessing and just blowing cash hand-over-fist.
I dunno. if it was easy it wouldn't be a problem. There are lots of dials to turn. As you say, qualification levels of teachers is is one, frequency of testing is another. I think the least effort improvement is just smaller classes.