Gates’s Survey Says: Test Score Growth Indicates Good Teacher


Teachers’ past success raising student performance on state tests was one of the strongest predictors of their ability to do it again, the Gates Foundation reported last week in preliminary findings from a $45 million study of teacher effectiveness in several cities.

The cautions on moving forward with “value-added” teacher evaluations (a class’s year-to-year growth in achievement measured in large part through gains on state tests) are many, for example:

  • Many teachers teach subjects that are not measured on state tests.
  • Students often rotate between multiple teachers.
  • Maturation and other circumstances can affect when students are more or less likely to show academic gains.

The Washington Post reports, “The central finding [from Gates] indicates that teachers with ‘value-added’ ratings are able to replicate that feat in multiple classrooms and in multiple years.” In addition,

  • Teachers with high “value-added” ratings are able to help students understand math concepts or demonstrate reading comprehension through writing.
  • The average student is able to recognize effective teaching.
  • Multiple sources of data can help teachers improve.

The final report from this project, including analysis of thousands of hours of videotaped lessons, is due in winter 2011–12.

For remarks on why tests scores can’t measure teacher effectiveness, check out 2009 National Teacher of the Year finalist Cindi Rigsbee’s “Teacher Effectiveness: More Than a Number” in Teacher Magazine.

Is Gates’s research helping spread good teaching practices, creating incentives to work with less-challenging students, or . . . ?