This week, Newsweek and Jay Mathews (both of the Washington Post) released their annual Challenge Index of top U.S. public high schools, which ranks schools based on the number of AP or IB tests given divided by the number of graduating seniors. People like lists, and the Challenge Index always gets a lot of attention despite being heavily criticized for inaccuracy and irrelevance. For example, the highest-ranking District school, Bell Multicultural High School, comes in......