Nearly half of Florida's high schools got an A grade for 2011-12, according to preliminary results released this morning.
The number of schools getting the top grade climbed to 231, compared with 148 for 2010-11, the Florida Department of Education said. That was a 16 percent jump.
The state said 47 percent earned an A and 31 percent a B. Three schools were given an F, down from six in 2010-11.
In Hillsborough County, Robinson and Strawberry Crest received an A for the first time. Thirteen of the district's 27 high schools got an A.
Middleton High improved to a B from a D. Nine other high schools in Hillsborough also received a B.
"We're proud of our high school students, teachers and administrators," Superintendent MaryEllen Elia said in a news release. "We have very high expectations and our students have shown that they are up to the task."
Comparisons with last year are difficult to make because of differing standards.
There were several measures in place to ease the transition into the more difficult grading. No school, for example, could drop more than one grade letter, and three more schools would have received an F if that protection were not in place, Education Commissioner Pam Stewart said. That will no longer be permitted when officials calculate grades for the current school year. They'll also use a higher bar for measuring writing proficiency and include geometry and biology performance.
Stewart could not say whether more schools would have scored lower if those measures were not held in abeyance.
"I can say that I think it will be more difficult to earn the same kinds of grades that we saw this year," Stewart said.
This year's grades are also the first to include exceptional student education center schools for those with disabilities. Those schools had a choice of receiving either a school improvement rating based on learning gains or a grade based also on performance.
Of those that chose to receive a grade, one received a D and 10 received an F. Seventy-two schools chose to receive an improvement rating instead.
The states grades its high schools based on student performance on the Florida Comprehensive Assessment Test as well as indicators of college readiness and participation in advanced classes.
The scores released Friday are preliminary as schools are given time to appeal the results.