Why some of N.J.'s top schools sunk so low in the state's new rankings

The score was nothing short of stunning for an affluent community such as Westfield, with its pricey school taxes and impressive SAT scores. 

On a scale of 0-100, Westfield Senior High School scored a 63.1 in a new school rating system released by the state last month, placing it in the 66th percentile.

That's worse than 120 other New Jersey high schools, according to an NJ Advance Media analysis of the results. 

"(The score makes it) appear that something is wrong," said Paul Pineiro, the district's assistant superintendent for curriculum, instruction and programs. "And that's just not the case."

Pineiro is correct: By all evidence, there is nothing seriously wrong with a high school that consistently ranks on Newsweek's list of the best high schools in the entire county. 

But what helped sink the state rating for the school -- where more than half of high school students opted out of their state math exam -- is a change in federal law that mandates counting thousands of students who skipped their annual state exams as if they had flunked them. 

The new way of accounting for students who opted out of the controversial PARCC exams in Westfield and other districts dragged down federal proficiency rates in English and math, which count for about a third of a high school's overall state rating.