Chronicle: In principle, setting a national entrance exam is the fairest way for China’s universities to determine which of the country’s millions of high-school students to admit each year. In practice, the exam is fraught with biases that favor children from Beijing, Shanghai, and other rich cities. Now, the Chinese government has begun a modest reform of university admissions. The grueling three-day exam, the gaokao, will remain, but universities will be free to apply their own supplemental criteria to select students.