His national ranking system for high schools, the Challenge Index, formerly in Newsweek, runs on the Washington Post’s website as the High School Challenge.
Challenge Cup | Challenge Tour | Challenge Anneka | University Challenge | Millennium Challenge Corporation | Science Citation Index | Human Development Index | Diamond Challenge Sculls | USA Pro Cycling Challenge | Roud Folk Song Index | Index Ventures | Challenge | The Great Indian Laughter Challenge | Infinite Challenge | index | WRU Challenge Cup | World Club Challenge | Sa Re Ga Ma Pa Challenge 2005 | Real World/Road Rules Challenge: Fresh Meat | Index term | Index on Censorship | Index Librorum Prohibitorum | Grand Challenge Cup | Fletcher Challenge | FIRST Tech Challenge | Extra Challenge | Ultimate Poker Challenge | The Man and the Challenge | Rachel's Challenge | Power Challenge |