Metrics such as ACT score, graduation rate, and other standardized test results contribute to their ranking results.
Here's what they wrote:
After two years at No. 2, Highlands High School is once again No. 1 in our annual Northern Kentucky high school ranking. Highlands High School is in the 99th percentile of schools in Kentucky according to the state’s ranking and its students earn an average ACT score of 24.3. Outside of class, students earned two Cappie awards (best featured actress in a play and best critic team) and a student was named Kentucky’s Mr. Baseball for the 2018 season.
6- Campbell County
9- Boone County
10- Simon Kenton