Greatschools.net has named Independence High School as the most improved school for the state of North Carolina. Here’s the criteria they used:

These schools showed the greatest improvement in test scores when comparing scores from the most recent year available to the year before. We compared grade-level improvement rather than student group improvement. For example, we compared 10th grade scores for this year to 10th grade scores last year, as opposed to comparing student scores in 10th grade and then the same group of students and their scores for 11th grade. It’s important to note that the improvement could be a result of the differences in the two sets of students rather than the success of the instruction. These schools also had to meet our minimum enrollment as outlined above for Top Performing Schools.