Boston Magazine retracts school rankings

And then in an extraordinary step on Friday, after the Globe and the magazine’s editors discovered additional errors in both the reporting and ranking methodology, Boston Magazine retracted the rankings entirely and removed the listing from its website.

Earlier in the week, when the magazine’s website published an editor’s note acknowledging the Austin Prep blunder and several other errors, editor Carly Carioli raised a fundamental question about the rankings: “Should we do them at all?’’

The answer, from a range of academicians, including some whose schools fared well in the rankings, was an emphatic no. One major reason: Boston Magazine gave major weight to SAT scores, even though 26 of the 65 schools wouldn’t disclose them. So those 26 were assigned an average of the scores for schools that did report, thereby placing them safely in the middle of the pack.

But beyond the arithmetic errors — enrollment numbers for at least 16 schools were misreported by the magazine, the Globe discovered — academic specialists and mathematicians said it made little sense to lump together tiny schools for special needs students; inner-city Catholic schools that serve underprivileged children; private day schools where tuition tops $40,000 a year; boarding schools that cost even more; and schools that are all boys or all girls.

“This is like comparing apples and aardvarks,’’ said Robert Gilpin, a retired Milton Academy history teacher who does consulting for parents whose students attend many of the schools in the rankings.

“Imagine the equivalent,’’ Gilpin said, “an attempt to rank together Charles River scullers, ultimate frisbee players, candlepin bowlers, and the starting lineup of the Red Sox. Everyone would laugh because the only thing they have in common is that each plays a sport.’’

So it is that the Tremont School in Weston, a tiny independent school that opened in 2011, was ranked as the 30th best private high school in the state, just behind Newton Country Day School and just ahead of Beaver Country Day School.

Tremont is among the 26 schools that didn’t share SAT scores with Boston Magazine — because it doesn’t have any. Kathy Trogolo, the assistant head of school, explained in an interview that Tremont only started its ninth grade class this month — with seven students. It will be three years before the school has its first SAT scores.

Even so, Tremont moved up in the rankings, to 29th, when Austin Prep nosedived. That placed Tremont a full 30 spots ahead of academically demanding Boston College High School, which finished 59th out of 65 schools in the magazine’s rankings.

Which left Gilpin and Michael G. Contompasis, a former Boston schools superintendent who was headmaster at Boston Latin School for 21 years, befuddled.

“Boston College High School has long been the best parochial high school in the state. It has always been the first choice among Catholic parents for the rigor of its education and the success of its students,’’ Contompasis said in an interview on Wednesday. Any quantitative ranking that places the Jesuit school near the bottom, he said, is “ridiculous.’’

Michele M. Daly, B.C. High’s senior vice president for institutional advancement, said no one from the magazine contacted the school — except for an advertising saleswoman asking the school to buy an ad package for more than $10,000.

At other schools, the reaction was mixed. Joshua Abrams, a mathematician who is the headmaster at Meridian Academy in Jamaica Plain, said he was pleased to learn that Boston Magazine had decided that the innovative nine-year-old school, with 38 students in grades 9 through 12, was the state’s seventh-best private high school. (It jumped to sixth once Austin Prep was downgraded.)

“It’s a lovely thing to get this kind of attention for the school,” said Abrams, who expressed happiness that the rankings took note of Meridian’s small class size, its 5-to-1 student-teacher ratio, and its relatively modest tuition, $23,900.

But Abrams said he believes that the 26 schools that chose to withhold their SAT scores should not have been ranked at all. The decision by the magazine and its outside mathematician, George Recck of Babson College, to rank the 26 schools by giving them an average of the SAT scores of the other 39 schools effectively rewarded those who withheld the information — and penalized some schools, like B.C. High, which make their SAT scores public.

Carioli said Recck was unwilling to discuss his methodology with the Globe.

More important, Abrams said, a school’s SAT scores “may reflect how much the school attracts good test takers in the first place. Average SAT scores do not measure the education that took place in the intervening years.’’ The SAT scores, he added, “are about one moment in time and not about growth and change.’’

There are other major errors in the data, which the Globe called to Carioli’s attention on Thursday. For at least 16 of the schools, the magazine used combined enrollment data for both high school and junior high grades and presented those numbers as high school enrollment data. That raised questions about the accuracy of the class size and student-teacher ratio rankings.

The Globe’s review of the rankings also found that the 65 schools included four that serve special needs students, including one, Willow Hill, that was ranked the state’s 12th best private high school.

On Thursday, before deciding to retract the rankings altogether, Carioli called the list an “outlier,’’ and expressed regret for the errors.

The last time Boston Magazine ranked private schools, in 2009, the listings were also a bit of an outlier. That year, Buckingham, Browne & Nichols was dropped to 27th place — after being ranked seventh, third, and fifth in prior years.

After the school’s newspaper, The Vanguard, turned up several errors in Boston Magazine’s computations, the magazine reordered its rankings, propelling BB&N into fifth place.

This year, the Cambridge school went back in the other direction. It was ranked ninth. But when the Austin Prep error was discovered, the magazine recalculated the rankings. In the shuffle, BB&N was dropped to 13th.

Walter V. Robinson can be reached at walter.robinson@globe.com.