Who needs a challenge?

Thanks to Helen for drawing my attention to this absurd school rating system:

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.

Got that? Only "average students" "need a challenge". So elite schools obviously have no place on a list of schools that challenge their students. Gifted kids can just twiddle their thumbs all day for all we care. Obscene anti-intellectualism aside, here are two more concerns about the Index:

(1) The arbitrary cut-off point means that the Index will give undue prominence to magnet and charter schools that fall just below this threshold, to the exclusion of comparable schools whose students do that little bit better. But why celebrate those wannabe-elite schools that are just mediocre enough to escape the cut-off? Why not just pick schools out of a hat?

(Though a few sentences later they seem to have forgotten about the gerrymandered restriction, claiming more broadly that their list represents "the top 5 percent of all 27,000 U.S. high schools in encouraging students to take AP, IB or Cambridge tests.")

(2) More fundamentally, is it even measuring a desirable outcome? It's always good for a school to offer advanced tests, so the challenge is there for the (probably few) students who are up to it. But there's nothing particularly commendable about forcing advanced tests upon ill-prepared students -- which seems to be what this rating system rewards. We need more information - e.g. pass rates - to tell whether these schools are pushing appropriate challenges on their students.

In light of these two points, it looks to me as though the 'Newsweek and Washington Post Challenge Index' is completely worthless.