How useful is the Greatschools rating?

I'm looking to move to a new area and am using the Greatschools rating that pops up on Zillow for a general idea of the quality of the school. Is it a fair assessment?

When you look up the rating on the website rather than Zillow it has some additional details. One of the schools we like has a 10 for test scores but a 5 for growth. What could cause students to test at the top of their state but not show growth on a year over year basis? There is another school very close that has high scores and high growth.

Submitted December 02, 2016 at 09:24AM by GeekDad12 http://ift.tt/2h2CtPU