Produced May 18, 2008; based on 2007 data

The Newsweek and Washington Post Challenge Index measures a public high school’s effort to challenge its students. The formula is simple: Divide the number of Advanced Placement, International Baccalaureate or Cambridge tests a school gave by the number of seniors who graduated in May or June. Tests taken by all students, not just seniors, are counted. Magnet or charter schools with SAT combined verbal and math averages higher than 1300, or ACT average scores above 29, are not included, since they do not have enough average students who need a challenge.

The rating is not a measurement of the overall quality of the school but illuminates one factor that many educators consider important.

The list below includes all public schools with a rating of 1.000. There are nearly 1,400 -- the top 5 percent of all 27,000 U.S. high schools in encouraging students to take AP, IB or Cambridge tests. Also listed are the name of the city or school district and the percentage of a school’s students whose family incomes are low enough to qualify for federally subsidized lunches and who also apply for that program (abbreviated in the list under the heading of Subs. Lunch). The portion of subsidized-lunch applicants is a rough indicator of a school’s poverty level. High-poverty schools are at a disadvantage in persuading students to take college-level courses, but some on this list have succeeded in doing so anyway.

The Equity and Excellence (abbreviated in the list under the heading of E&E) rate is the percentage of all seniors who have had at least one score on an AP, IB or Cambridge test that would qualify them for college credit. The average AP Equity and Excellence rate for all U.S. schools is about 15 percent.

If you have 2007 data showing that your school should be on this list, please contact Jay Mathews at challenge@washpost.com. To comment on the list, please click here.

**Includes IB or Cambridge. All other schools use just AP.