Education is still far from being a knowledge industry, in the sense that its own practices are being continuously transformed by greater understanding of their efficacy. While in many other fields, people enter their professional lives expecting that what they do and how they do it will be transformed by evidence and research, this is still not generally the case in education. Transforming teaching does not just involve high quality recruiting and initial education; it also requires that those who are now teaching adapt to constantly changing demands. In some countries, this is also a massive quantitative challenge: China alone has 12 million teachers, many of whom are in rural areas and in need of significant upgrading of their skills to cope with rapidly changing demands on schools.