File photo of the campus grounds of the Bill and Melinda Gates Foundation in Seattle

 
File photo of the campus grounds of the Bill and Melinda Gates Foundation in Seattle
The campus grounds of the Bill and Melinda Gates Foundation in Seattle are pictured in this file photo from November 4, 2011. A three-year, $50 million study, funded by the Bill & Melinda Gates Foundation and released January 8, 2013, found that effective teachers can be identified by observing them at work, measuring their students' progress on state standardized tests -- and asking those students directly how much they're learning. REUTERS/Anthony Bolante/Files