The best way is to take a sampling of students who attended that school and ask them directly. As someone who runs a school, all the review sites are so easily

The best way is to take a sampling of students who attended that school and ask them directly. As someone who runs a school, all the review sites are so easily gamed it's not even a data point you should consider. I've literally seen schools ask, "Did you have a good experience?" If yes -> go leave a review, if no -> submit this feedback form. Like it's the app store.