The University of Arizona was ranked 77th out of 1,250 schools in 74 countries in the newest U.S. News and World Report Best Global Universities ranking.

ASU ranked 134 and NAU ranked 654.

Harvard was ranked No. 1 overall, followed by the Massachusetts Institute of Technology, Stanford and the University of California-Berkeley. The United Kingdom’s University of Oxford was ranked No. 5.

Earlier this year, the 2018 U.S. News and World Report ranked the UA the 124th-best college in the country, and ASU 115th. So why is the UA ranked higher in this ranking, when universities from around the globe are added to the equation?

The scoring system is different.

“The schools that rank the highest in the Best Global Universities rankings are those that emphasize academic research, including by partnering with international scholars to produce highly cited articles,” said Robert Morse, chief data strategist at U.S. News, in a statement.

“This is different from the Best Colleges rankings, which measure the overall quality of undergraduate institutions in the U.S. and focus on student outcomes such as graduation and retention rates,” he said.

U.S. News collected a pool of 1,295 schools for ranking. Of those, 250 were taken from the top results of Clarivate Analytics’ global reputation survey.

The schools considered were required to publish a minimum of 1,500 papers between 2011 and 2015. Because of this criteria, a few graduate-only schools were eligible for inclusion in the final rankings.

Once the schools were identified, the rankings were determined by 13 factors of varying weight to measure global research performance, which roughly broke down to reputation and academic opinion of other departments; international collaboration; and number of publications, conferences and references by other academics.

The U.S. leads the rankings with a total of 221 universities, followed by China with 136, Japan with 76, The U.K. with 73 and Germany with 58.

The University of Arizona’s No. 77 ranking slipped slightly from the 2017 list, when it ranked 73rd.

You can find the full ranking list, FAQs and detailed methodology here: usnews.com/education/best-global-universities

Contact Mikayla Mace at mmace@tucson.com or 573-4158. On Twitter: @mikaylagram