How Should Teachers Be Rewarded? We never forget our best teachers-those who inspired us with a deeper understanding or an enduring passion, the ones we come back to visit years after graduating, the educators who opened doors and altered the course of our lives. It would be wonderful if we knew more about such talented teachers and how to multiply their number. How do they come by their craft? What qualities and capacities do they possess? Can these abilities be measured? Can they be taught? Perhaps above all:How should excellent teaching be rewarded so that the best teachers--the most competent, caring and compelling--remain in a profession known for low pay and low status? Such questions have become critical to the future of public education in the U.S. Even as politicians push to hold schools and their faculty members responsible as never before for student learning, the nation faces a shortage of teaching talent. About 3.2 million people teach in U.S. public schools, but, according to an estimate made by economist William Hussar at the National Center for Education Statistics, the nation will need to recruit an additional 2.8 million over the next eight years owing to baby-boomer retirement, growing student enrollment and staff turnover (人员调整)--which is especially rapid among new teachers. Finding and keeping high-quality teachers are key to America's competitiveness as a nation. Recent test results show that U.S. 10th-graders ranked just 17th in science among peers from 30 nations, while in math they placed in the bottom five. Research suggests that a good teacher is the single most important factor in boosting achievement, more important than class size, the dollars spent per student or the quality of textbooks and materials. Across the country, hundreds of school districts are experimenting with new ways to attract, reward and keep good teachers. Many of these efforts borrow ideas from business. They include signing bonuses for hard-to-fill jobs like teaching high school chemistry, housing allowances and what might be called combat pay for teachers who commit to working in the most distressed schools. But the idea gaining the most motivation--and controversy--is merit pay, which attempts to measure the quality of teachers' work and pay teachers accordingly. Traditionally, public-school salaries are based on years spent on the job and college credits earned, a system favored by unions because it treats all teachers equally. Of course, everyone knows that not all teachers are equal. Just witness how hard parents try to get their kids into the best classrooms. And yet there is no universally accepted way to measure competence, much less the great charm of a truly brilliant educator. In its absence, policy-makers have focused on that current measure of all things educational: student test scores. In districts across the country, administrators are devising systems that track student scores back to the teachers who taught them in an attempt to assign credit and blame and, in some cases, target help to teachers who need it. Offering bonuses to teachers who raise student achievement, the theory goes, will improve the overall quality of instruction, retain those who get the job done and attract more highly qualified candidates to the profession--all while lifting those all-important test scores. Such efforts have been encouraged by the Bush Administration, which in 2006 started a program that awards $99 million a year in grants to districts that link teacher compensation to raising student test scores. Merit pay has also become part of the debate in Congress over how to improve the 2001 No Child Left Behind Act. Last summer, Barack Obama signed merit pay at a meeting of the National Education Association, the nation's largest teachers' union, so long as the measure of merit is 'developed with teachers, not imposed on them and not based on