Newsweek just released its new high school rankings, beginning a great adventure as an arbiter of educational quality. I welcome the magazine as the latest member of the School Rating Scoundrels Club, a small organization with many detractors but a desire to be helpful.

Huh? Hasn’t Newsweek been doing school rankings since 1998? How can it be a new member?

The confusing answer is that I, the founding member of the club, was the originator of Newsweek’s America’s Best High Schools list in 1998. I supervised the Newsweek list, based on my Challenge Index ratings of college-level test participation in high schools, until this year when I moved that list and its contrarian methodology to The Washington Post.

I made the switch because the Washington Post Co., my employer for 40 years, sold Newsweek last summer. The Post’s new list, called the High School Challenge, has been posted on since May 22.

The people who bought Newsweek seemed smart and conscientious. They wanted to talk about keeping me in my freelance list-making role for them. But I said no. They showed their good character by resisting the impulse to toss the list into a trash bin as a relic of the old regime. Instead they have created their own list based on a different way of rating schools.

This takes some courage. Many educators hate these lists. Some principals tell me such ratings trivialize the many wonderful and complex features of their high schools. They have a point, but many readers, particularly parents, tell me they think they are smart enough to figure out what is useful, and what is useless, in my ratings, and others.

I love having a new list to compare to mine. Whenever a competing list comes out, the page views for the Challenge Index list go up as people check out all the alternatives (or in some cases, I suspect, become confused about which list is which.)

Everything I say on this issue should be viewed with skepticism. I am talking about my long-cherished ideas and about what competing news organizations are doing with them . But I have been rating high schools longer than anybody else, and so feel as grandfatherly to new school rankings as I do to Los Angeles residents Ben Mathews, age 2, and Tom Mathews, age 5 months.

The Challenge Index list uses only one factor — the ratio of college level tests to graduating seniors — to rank schools. The Post team putting it together gives readers a wealth of information about each of the schools listed, but the ranks are based solely on participation rates on tests like Advanced Placement and International Baccalaureate. Many readers tell me they like the simplicity and the fact that they can easily calculate the Challenge Index rating of any high school in their neighborhood, even if its numbers are not good enough to make the Post’s national list. Critics say it is way too simple.

The new editors of Newsweek have adopted the more complex approach of other list makers, such as U.S. News & World Report. They weigh several factors in calculating the rating of each school. Twenty-five percent of the new Newsweek rating is based on the same college-level test participation numbers I use. It also devotes 25 percent to the school’s graduation rate and 25 percent to its college matriculation rate. SAT or ACT score averages make up 10 percent, average college-level test scores are another 10 percent and the number of AP courses offered determines the remaining 5 percent.

Newsweek’s introduction to its new list says this formula is designed to reflect “a school’s success turning out college ready (and life-ready) students.” That is an admirable sentiment, but I think giving such weight to graduation, college-going rates, and SAT or ACT scores takes the magazine further from, rather than closer to, its goal.

Graduation rates and college-going rates are closely tied to the average incomes of parents. Schools in affluent neighborhoods usually have graduation rates above 90 percent. Schools in poor urban neighborhoods often graduate only half of their students, if you calculate graduation — as schools have begun to do — by the percentage of ninth-graders who receive diplomas four years later.

Schools that do poorly on those measures try to improve, but few have found a way to escape the iron rule that poverty significantly lowers the chances of getting out of high school and into college. The only sure-fire way for the hard-working staffs of those schools to improve their numbers is to expel the poor students and fill their spaces with rich ones, a strategy that is not only illegal but morally reprehensible.

The Challenge Index also favors affluent schools to an extent, but not nearly as much as the new Newsweek formula. I designed my list to embrace the philosophy of schools like Garfield High School in East Los Angeles, where I first learned the power AP had to change the cultures of poverty-stricken high schools. The schools that qualify for my list have more average and below average students than are usually found on best schools lists. The Challenge Index measures not test scores or graduation rates, but the work of educators trying to get as many students as possible into college-level courses and tests. It recognizes schools that try to raise the level of every child, no matter how low their starting points.

I exclude from my list any public magnet or charter schools that are so selective that their average SAT or ACT scores are higher than the highest average for any regular enrollment school in the country. As a result, the Post’s list is full of schools in all kinds of neighborhoods. It has none of the ultra-selective schools with no room for average children who want to improve.

The difference in evident when you look at the average poverty rate for the top 50 schools on the new Newsweek list and the top 50 on the Washington Post’s new High School Challenge list. The average portion of low-income students for the 45 schools on the Newsweek list for which that data is available is 19.6 percent. The comparable portion on my list for the 48 schools that gave me poverty data is 31.8 percent.

Such differences produce interesting and useful conversations about what makes a great school. We school rating scoundrels have a good time when we get together to talk about this. I think the new Newsweek listmakers, almost none of whom I know, will enjoy reviewing their data and seeing if there are other measures they want to include.

Newsweek didn’t give itself much time to get this list done. High schools received the forms only a month before they were due, not a good idea when you are dealing with busy educators at the end of the school year. Newsweek said it received data from only 1,100 schools, compared to the 4,000 to 5,000 potentially eligible schools we examined for the Post’s new list. Newsweek ranked only 500 schools. We ranked about 2,000.

The Post and Newsweek lists share only 22 schools in their top 50. The Newsweek list has 11 schools that I kept off the Post list because of their selectivity, putting them instead on our separate Public Elites list.

The short deadline appeared to leave holes in the Newsweek list. It has no schools from Fairfax or Arlington counties in the Washington area, and missed many other schools around the country that were almost sure to qualify because of their affluent student bodies.

Next year will be different. Perhaps not only Newsweek, but some of the smart educators who have been telling me they know better ways to rate schools will unveil their own lists.

That would be good. I think high schools define American lives, and reveal our most important and persistent educational failings. I look forward to any excuse to write more about them.