What follows is the description of the four part ranking system they used and is copied directly from their faq's page:
6. How were schools evaluated using the four-step process? What data and/or indicators were used to identify the high schools?
Analysts from RTI, who implemented the U.S. News comprehensive rankings methodology, used several indicators to determine which high schools met the four-step criteria as outlined in the Best High Schools rankings methodology. These indicators include:
• Step 1: Overall performance of students on state tests
Performance index for each high school in each state (all students)
An index that measures the mastery of state tests, with full credit awarded to proficient scores, additional credit awarded to more advanced scores and partial credit awarded to scores approaching proficient. This performance index was computed for each high school based on student performance on 2015-2016 state reading and mathematics assessments.
Economically disadvantaged students as a percent of total enrollment
A measure of student poverty, which is typically the percentage of each high school's total enrollment receiving free or reduced-price lunch. This used federal data from the U.S. Department of Education's website.
Risk-adjusted performance index
Each high school's residual, which measured the degree to which a high school differed from its statistically expected performance on reading and mathematics assessments, given the proportion of economically disadvantaged students, was used to establish a performance zone.
High schools with risk-adjusted performance index values at or above the upper threshold of the performance zone of one-third of a standard deviation were considered performing beyond expectations. These schools passed Step 1 of the U.S. News methodology and advanced to Step 2.
Absolute performance
A school could also pass Step 1 by performing in the top 10 percent of schools in its state on reading and mathematics assessments, regardless of its poverty level. In addition, a school was barred from passing Step 1 if it performed in the bottom 10 percent of schools in its state.
• Step 2: Identify high schools that performed at or better than the state average for their historically underserved students
Combined reading and mathematics proficiency rate for historically underserved student subgroups for each high school
Reading and mathematics proficiency rate is a weighted average of the percentage of students for each group at or above the proficient level.
State average combined reading and mathematics proficiency rate for historically underserved student subgroups
A weighted state average for the historically underserved student subgroups was calculated using student subgroup performance across all high schools in the state.
Historically underserved students performance gap differential
The differential between a school's historically underserved student performance index and the state average for that index. Only values greater than or equal to zero meet the criteria for selection.
Values greater than or equal to zero indicated that a high school's historically underserved student subgroups outperformed the state average. Values lower than zero meant that a high school's historically underserved student subgroups performed worse than the state average.
High schools that do as well as or better than the state average
High schools with historically underserved student subgroups that performed as well as or better than the state average advanced to Step 3. That is, all high schools that had a value of zero or higher for the historically underserved student proficiency gap differential passed Step 2.
High schools that passed Step 1 and did not have historically underserved student subgroups automatically moved to Step 3.
• Step 3: Identify schools that have surpassed a basic standard for high school graduation rates
High school graduation rate
For the 2018 rankings, a school's graduation rate reflects the 2016 graduation cohort, which is made up of students who entered ninth grade in the 2012-2013 school year.
National standard graduation rate
High schools were only allowed to pass Step 3 if their rounded graduation rate was 80 percent or greater. This U.S. News standard was drawn from federal law that requires states to give additional resources to schools that do not achieve higher than a 67 percent graduation rate.
Schools without a graduation rate value were allowed to pass Step 3 to account for varying state rules regarding which high schools receive a calculated graduation rate, since each high school has limited control over this.
• Step 4: Performance on college-level AP and IB exams to determine national gold, silver and bronze medal winners
AP and IB participation percent
The percentage of 12th-graders in 2015-2016 who took at least one AP or IB exam at some point during high school �" the number of students who took AP or IB tests divided by the total number of 12th-graders enrolled at the school. In schools where results for both AP and IB were reported, both participation rates were calculated.
Quality-adjusted AP and IB participation percent
The percentage of 12th-graders in 2015-2016 who took and passed at least one AP and IB exam at some point during high school �" the number of students tested who received at least one score of 3 or higher on an AP test or 4 or higher on an IB test, divided by the total number of 12th-graders enrolled at the school. In schools where results for both AP and IB were reported, both quality adjusted participation rates were calculated.
College Readiness Index to determine gold, silver and bronze medal winners
An unrounded index �" presented at one decimal place in the published rankings online �" that measures the degree to which a school's students are exposed to, and pass, some college-level material (a weighted average of AP and IB participation, weighted at 25 percent of the CRI, and the quality-adjusted AP and IB participation rate, weighted at 75 percent of the CRI).
For schools that reported both AP and IB results, U.S. News created a blended CRI that gave a proportionally larger weight to the program that had a higher participation count.
Only CRI values greater than 21.51 �" the 2018 Best High Schools median CRI �" meet the criteria for selection as gold and silver medal winners.
Gold medal high schools are simply the top 500 high schools that met this CRI criteria; the 2,211 schools ranked 501 through 2,711 �" the silver medal schools �" also met this CRI criteria. An additional 3,237 high schools that passed the first three steps in the methodology were awarded bronze medals and are listed alphabetically.
A tiebreaker was used when schools have the same unrounded CRI so that each school has a different number rank.
The tiebreaker measures the degree to which students take and pass a wide variety of AP and IB courses across the multiple disciplines for which AP and IB offers tests.
For more information, see the U.S. News Best High Schools rankings methodology, or read the much longer and more detailed technical appendix that RTI produced.
