Accomplishing health education reform. The perspectives of the Finnish secondary school teachers

When the students are retested in June, Mrs. BrownБЂ™s class scores at the seventieth percentile, while Mr. SmithБЂ™s students have fallen to the fortieth percentile. That change in the studentsБЂ™ rankings, value-added theory says, is a meaningful indicator of how much more effective Mrs. Brown is as a teacher than Mr. Smith. ItБЂ™s only a crude measure, of course. A teacher is not solely responsible for how much is learned in a classroom, and not everything of value that a teacher imparts to his or her students can be captured on a standardized test. Nonetheless, if you follow Brown and Smith for three or four years, their effect on their studentsБЂ™ test scores starts to become predictable: with enough data, it is possible to identify who the very good teachers are and who the very poor teachers are. WhatБЂ™s more БЂ“ and this is the finding that has galvanized the educational world БЂ“ the difference between good teachers and poor teachers turns out to be vast. Eric Hanushek, an economist at Stanford, estimates that the students of a very bad teacher will learn, on average, half a yearБЂ™s worth of material in one school year ...»