U.S. News & World Report just published its 2019 “Best High Schools” rankings — and the top 10 looks mighty different from 2018.

(It may make you wonder whether the 2018 wasn’t the “best.” But never mind.)

Last year, seven of the top 10 high schools were charter schools — six from the same charter chain. In the newly released 2019 rankings, seven of the top 10 are schools from traditional public school systems, most of them magnet schools; three are charters.

Last year, the top school was a charter school in Arizona, which dropped to No. 3 for 2019. In the ranking just out, the top campus is a magnet school in South Carolina, which wasn’t in the top 10 last year. Meanwhile, the magnet Thomas Jefferson High School for Science and Technology in Virginia’s Fairfax County Public Schools jumped from No. 10 in 2018 to No. 4 in 2019.

Did the schools really change all that much in a year? Of course not.

U.S. News says it dramatically changed the way it decides what the “best” high schools are (even though in years past it has assured us those lists represented the “best”) — and, accordingly the results are different. It made the changes, it said, “with students, parents, educators and the general public in mind,” so that the rankings would be “easier to understand, more thorough and include as many schools as possible.”

Here’s how the magazine explains the changes:

How Different Are the Revamped 2019 Best High Schools Methodology and Rankings?
Very different. In the previous methodology, rank order was determined solely using the College Readiness Index, based on performance on and participation in Advanced Placement and International Baccalaureate exams. In the revised methodology, six ranking factors are used, each of which are weighted to produce an overall score on which the ranking is based.

In 2018, the sole indicator was participation by high school seniors in an Advanced Placement or International Baccalaureate exam, meaning 100 percent of the rankings were based on standardized tests.

As it turns out, the six factors used by the magazine for its 2019 rankings mostly involved standardized test participation or scores (90 percent) with graduation rates accounting for the remaining 10 percent. But different tests are included and so are different ways of looking at them. (We won’t dwell on the fact that standardized test scores provide a very limited look at what students know and can do. Nor will we fixate on the fact that graduation rates can, and have been, fudged in the past.)

U.S. News said that in addition to the changes in the indicators used in its calculations, it ranked more than 17,000 high schools this year, compared with 2,700 in 2018.

As a result, U.S. News said, “Since the methodology changed so significantly this year, a school’s ranking in the 2019 Best High Schools ranking can’t be compared with its rankings in any previous U.S. News ranking.”

Here’s the 2019 Top 10, followed by the 2018:

  1. Academic Magnet High School — a magnet school in South Carolina’s Charleston County School District
  2. Maine School of Science and Mathematics — a magnet school in Limestone, Maine, that was created and operated by the state legislature
  3. BASIS Scottsdale — a charter school in Scottsdale, Ariz.
  4. Thomas Jefferson High School for Science and Technology — a magnet school in Virginia’s Fairfax County
  5. Central Magnet School — a magnet school in Tennessee’s Rutherford County
  6. Gwinnett School of Mathematics, Science and Technology — termed a “special school” that accepts students from across Georgia’s Gwinnett County. It was a charter school but relinquished the charter several years ago.
  7. Haas Hall Academy — a charter school in Fayetteville, Ark.
  8. International Academy of Macomb — a magnet school in Michigan’s Chippewa Valley Schools
  9. Walter Payton College Preparatory High School — a magnet school in Chicago Public Schools
  10. Signature School — a charter school in Evansville, Ind.

The three charter schools are BASIS Scottsdale, Haas Hall Academy and Signature.

This was the 2018 Top 10 list:

  1. BASIS Scottsdale, Ariz.
  2. BASIS Chandler, Ariz.
  3. BASIS Oro Valley, Ariz.
  4. BASIS Tucson North, Ariz.
  5. BASIS Flagstaff, Ariz.
  6. Meridian School, Round Rock, Tex.
  7. International Academy of Macomb, Clinton Township, Mich.
  8. BASIS Peoria, Ariz.
  9. Baccalaureate School for Global Education, New York
  10. Thomas Jefferson High School for Science and Technology, Fairfax County, Va.

The charter schools on the 2018 list were the BASIS schools plus the Meridian School.

Charter schools are publicly funded but independently operated and are not required to follow all of the same rules that traditional public schools must. Magnet campuses are special schools within — and operated by — traditional public school systems and offer special instruction or programs designed to attract a diverse student body.

So what changed in the methodology for 2019? Here are the six factors:

College Readiness (30 percent) — This reflects the number of seniors in a high school class who took an Advanced Placement or International Baccalaureate exam and their scores. It’s worth noting that the 2018 College Readiness rating included both AP and IB scores for the first time; IB was not used before 2018.

Math and Reading Proficiency (20 percent) — This reflects the results of state standardized tests measuring student proficiency in subjects related to mathematics and reading. It’s “a simple measure of schools’ student performance on these assessments,” the magazine says, which is different from the next indicator.

Math and Reading Performance (20 percent) — This comes from the same state standardized tests in math and reading — but in this case, “the total assessment scores are compared with what U.S. News predicted for a school with its demographic characteristics in its state,” the magazine says.

Underserved Student Performance (10 percent) — Here’s how U.S. News explains this one: This is a measure assessing learning outcomes only among black, Hispanic and low-income students. This evaluates how well this underserved subgroup scored on state assessments compared with the average for non-underserved students among schools in the same state. Schools performing above the 50th percentile nationally in this comparison received the highest score, while other schools’ scores decreased the greater the distance between their underserved students and their state’s median for non-underserved students.”

College Curriculum Breadth (10 percent) — The proportions of 12th-graders who took and passed AP and IB exams in multiple areas. More exams are valued more than fewer exams up to a maximum of four. Passing an exam is worth three times more than taking an exam.

Graduation Rate (10 percent) — This is a measure of the proportion of students who entered ninth grade in the 2012-2013 academic year and graduated by 2016-2017. The magazine says, “Graduation rates are an important indicator of how well a school is succeeding for all its students” (even though it has only 10 percent weight in the overall rankings).

For the record, here’s what the magazine says it did:

In coordination with North Carolina-based RTI International, a global nonprofit social science research firm, U.S. News ranked 17,245 public high schools out of more than 23,000 reviewed. This is the count of public high schools that had a 12th grade enrollment of 15 or greater, or otherwise had sufficient enrollment in other high school grades during the 2016-2017 school year to be analyzed. It is six to seven times larger than the more than 2,700 ranked schools in the 2018 edition.
We did this by summing their weighted scores across six indicators of school quality, then computed for each school a single zero to 100 overall score reflective of performance across these metrics. The overall scores depict how well each school did on a national percentile basis. For example, a school with a score of 60 performed in the 60th percentile among all schools in the rankings.

Here is what the magazine says are the results:

This is a big change from last year’s rankings where schools were ineligible to be ranked if they came up short on state assessments or graduation rates. Back then, only schools performing well enough on those factors were included; their rank order determined entirely by U.S. News’ College Readiness Index -- measuring AP and IB exam participation and performance.
With the revamped methodology, most schools’ ranks changed significantly between 2018 and 2019 because of the broader competition in terms of the number of schools being newly ranked -- more than 14,500. Consequently, a school’s rise or fall in the 2019 rankings does not necessarily reflect a difference in its underlying data. Since the methodology changed so significantly this year, a school’s ranking in the 2019 Best High Schools ranking can’t be compared with its rankings in any previous U.S. News ranking.

And here’s why the magazine said it made its changes:

With students, parents, educators and the general public in mind, U.S. News made improvements to the rankings so that they’re easier to understand, more thorough and include as many schools as possible.
The revamped Best High Schools methodology enables users to more easily understand why some schools place ahead of others. Each school’s rank is linked to a single overall zero to 100 score instead of a labyrinthine filtering process that perplexed readers. For example, under the new methodology, a school with an overall score of 78 has placed in the 78th percentile nationally and thus is ranked more highly than a school with a score of 77. Under the old methodology, there was no overall score. A highly ranked school one year could become unranked the next year because marginal changes in its data placed it on the wrong side of a filtering threshold.