‘Vergara’ decision signals the start of a third wave of education reform

The June court ruling against teacher employment laws in California was the opening salvo in a battle that has already moved to New York and will likely spread from there. It also could mark the beginning of a third great era of U.S. education reform — one that focuses not on inputs or outcomes but on the workings of schools themselves.

Moments before closing arguments began in the landmark case Vergara v. California, Judge Rolf M. Treu asked those in his courtroom to stand, turn and look at two portraits:...