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