In June 2009, The New Teacher Project's study, "The Widget Effect: Our National Failure to Acknowledge and Act on Differences in Teacher Effectiveness", drew national attention to the issue of ineffective teacher evaluation systems. The study documents how teacher evaluation systems ignore variations in performance, giving virtually all teachers positive ratings despite the fact that teachers and principals both say poor performance is common. As a result, excellence goes unrecognized, poor performance goes unaddressed, and a teacher's instructional effectiveness almost never factors into critical decisions such as how teachers are hired, developed or retained. To reverse the "widget effect," the study recommends that states and school districts: (1) Adopt a comprehensive performance evaluation system; (2) Train administrators and other evaluators; (3) Integrate the performance evaluation system; and (4) Address consistently ineffective teaching. The New Teacher Project believes that the widget effect represents the single greatest challenge to improving teacher effectiveness and eliminating educational inequality. Until a teacher's effectiveness is accurately measured and matters in decision-making, the nation's schools will never be able to build a thriving teacher workforce capable of realizing sustainable improvement or closing the achievement gap. Shifting federal education policy to focus on measuring and responding strategically to differences in teacher effectiveness is essential, and the upcoming reauthorization of the Elementary and Secondary Education Act (ESEA) creates an opportunity to realize this shift. (Contains 5 footnotes.)