Across the globe, countries are trying to raise their educational achievement. There is enormous attention to and debate about getting the policy infrastructure right, but policies won't achieve results without building the capacity of schools to carry them out. Increasingly, the quality of teachers is seen as a if not the crucial factor in delivering high-quality education. So, the challenge of preparing high-quality teachers is central to every country's agenda. This challenge is becoming more acute as the roles of teachers change. Teachers are now expected to prepare students to become knowledge workers, not just factory workers; to produce higher-order cognitive skills; to help every child succeed, not just the easy to teach; to address the increasing ethnic diversity of most school systems; and to adapt to and harness new technologies--all in the context of increasingly rapid globalization. Schools need even higher-quality teachers in the future than in the past. There is much innovation in the United States and internationally on this issue. Take Singapore, for example. Singapore has gone from being a third-world to a first-world economy in the space of 40 years and from being a low-performing education system to one that produces world-class performance on a range of international assessments. How has teacher education played a role in this and how is teacher education in Singapore now moving from a 20th- to a 21st-century model? Changing a System When Singapore became independent in 1965, it was an impoverished country where many children didn't attend school at all. The goal at that point was to establish universal primary education as soon as possible, so there was mass recruitment of teachers, crash programs, and a dilution of standards. By the 1970s, demand had stabilized somewhat and attention shifted from quantity to quality of teachers and of training. The Institute for Education was created in 1973 as the single teacher education and professional development institution for Singapore, and the expanding secondary school sector led to a greater focus on specialized teachers, especially in math, science, and vocational education. In the 1990s, another broad set of changes was made to increase the quality and attractiveness of the teaching profession. As part of this, the Institute of Education became the National Institute of Education (NIE), an autonomous unit of Nanyang Technological University. New degrees were introduced, and research to improve teaching and inform policy development became a more significant part of NIE's mission. The preparation of teachers in Singapore is regarded as a lifelong enterprise. Graduates are recruited from the top third of their high school class. Financial support is provided during training, and initial compensation is comparable to salaries for graduates in other professions. All new teachers experience mentoring and induction, and the country has a serious commitment to ongoing professional development--an entitlement of 100 hours a year. As a result, Singapore has very little teacher attrition, and the profession is attractive to men as well as women (30% of teachers are males). By the end of the 20th century, the system had produced top-level performance on international assessments, and the National Institute of Education had also become recognized as one of the premier teacher training institutions in the world. No Time to Rest However, even strong systems cannot afford to be complacent. In September 2009, Singapore passed another milestone in this journey of continuous innovation. NIE released its new Teacher Education Model for the 21st Century ([TE.sup.21] for short). Based on the premise that education must urgently respond to the global, technology-driven, knowledge economy, the central theme of [TE.sup.21] is that 21st-century learners need 21st-century teachers and that teacher education therefore needs to rethink its core assumptions in this new context. …