The type of teacher data you see on GreatSchools.org is determined by the information your state Department of Education makes available to the public. This information varies by state. In California, for example, you can learn the average number of years of experience teachers have and the percentage of teachers who have credentials. In Florida you can see the percentage of teachers with advanced degrees and the percentage of teachers who are teaching out of their field of expertise. Where available, you'll find this information under the School Environment tab on the school profile.