Bartow High ranked 168 out of 1,623 schools listed by the magazine. Last year the school ranked 142 of 1,557 schools, its highest ranking ever.

Bartow High also includes an International Baccalaureate program and Summerlin Academy, a military school.

Ed Vetters, principal of the IB program, said student and faculty efforts at both the IB school and Bartow High help the school do well on the list each year.

“We’re constantly pushing to encourage students to take AP exams and do well on them, and that’s one of the major factors in the (Newsweek) indexing,” he said. “We’re proud to be representing Polk County.”

The IB program has helped increase the scores on the Newsweek list in the past because of the method used to rank schools, Newsweek contributing editor Jay Mathews said.

Mathews compiles the school list each year. He divides the total number of International Baccalaureate, Advanced Placement and Cambridge tests taken by students at a school each year by the number of graduating seniors. This score becomes a school’s Challenge Index, which is used to rank schools throughout the country.

An IB program often boosts a school’s score each year because the program usually requires students to take IB exams. Only about 70 percent of students enrolled in AP courses take the AP tests nationwide, however, which can lower the scores of schools without IB programs, Mathews said.

Mathews said Newsweek’s scoring system shows how important it is for schools to encourage AP students to take the tests, which can help them earn college credit.

The number of schools listed by the magazine each year varies because any school with an index of at least 1.000, meaning it had as many tests as graduates, is included. When Newsweek started the list in 1998, only about 240 schools achieved that score. This year, more than 1,600 did, Mathews said.

Bartow High’s index score this year was 3.443, putting it within the top 1 percent of high schools in the U.S. The school had 316 graduates this year, but its students took more than 800 AP tests and more than 300 IB tests, Mathews said.

“Bartow High is one of those schools I’m particularly happy to see on the list because it contradicts the idea that schools with low-income kids cannot perform academically,” Mathews said.

Forty percent of Bartow High’s 1,881 students were eligible to receive lunch subsidies because of low family income levels, according to Newsweek’s online profile of the school.

The article can be read only online at http://www.newsweek.com/.