Even critics of No Child Left Behind acknowledge that the explosion of data about student performance, finances and teacher effectiveness that the law ushered in is a boon for efforts to improve U.S. schools. Plenty of challenges remain, but the development of better educational data systems is a quiet success story of the last 10 years. Guidera, who leads the national Data Quality Campaign, is widely credited for playing a key role in prodding states to improve their data systems and publicly holding them accountable for doing so. But that was the easy part. In 2012 she must help states move from just collecting data to actually using it to inform decision-making, make sure state data efforts are aligned with initiatives like the Common Core academic standards that 46 have committed to adopt and do this while placating critics on the political right and left who fear that data systems are a stalking horse for a national school system. That’s conspiratorial nonsense, but not everyone is excited about this new era of transparency, which is trying to clean out education’s dark corners.