• Getting the right people to become teachers (the quality of an education system cannot exceed the quality of its teachers);
• Developing them into effective instructors (the only way to improve outcomes is to improve instruction); and
• Ensuring that the system is able to provide the best possible instruction for every child (high performance requires every child to succeed).
The McKinsey report concludes: “The available evidence suggests that the main driver of the variation in student learning at school is the quality of the teachers.” Three illustrations are provided to support this conclusion:
• Ten years ago, seminal research based on data from the Tennessee Comprehensive Assessment Program tests showed that if two average 8-year-old students were given different teachers—one of them a high performer, the other a low performer—the students’ performance diverged by more than 50 percentile points within 3 years.28
• A study from Dallas showed that the performance gap between students assigned three effective teachers in a row and those assigned three ineffective teachers in a row was 49 percentile points.29
• In Boston, students placed with top-performing math teachers made substantial gains, while students placed with the worst teachers regressed—their math actually got worse.
The McKinsey report further concluded as follows:
Studies that take into account all of the available evidence on teacher effectiveness suggest that students placed with high-performing teachers will progress three times as fast as those placed with low-performing teachers.
The second McKinsey report (2010) addresses the teacher talent gap by examining the details of teacher preparation and performance in three top-performing countries: Singapore, Finland, and South Korea.30 These
28 W. Sanders and J. Rivers, 1996, Cumulative and Residual Effects of Teachers on Future Student Academic Achievement. University of Tennessee, Value-Added Research and Assessment Center, Knoxville, Tenn.
29 Heather R. Jordan, Robert L. Mendro, and Dash Weerasinghe, 1997, “Teacher Effects on Longitudinal Student Achievement: A Report on Research in Progress,” Presented at the CREATE Annual Meeting Indianapolis, Ind. Available at http://dallasisd.schoolwires.net/cms/lib/TX01001475/Centricity/Shared/evalacct/research/articles/Jordan-Teacher-Effects-on-Longitudinal-Student-Achievement-1997.pdf.
30 Byron Auguste, Paul Kihn, and Matt Miller, 2010, “Closing the talent gap: Attracting and retaining top-third graduates to careers in teaching.” McKinsey & Company, September.