Between 1992 and 2011, the improvement in achievement by Wisconsin students was the fourth worst of the 41 states for which data are available. In that relatively short time, Wisconsin moved from sixth to 14th in the rankings. This signaled a fundamental set of problems ranging from the future earnings of Wisconsin students to the growth and prosperity of the entire state.

New York City's schools chancellor, with the support of Mayor Bloomberg, wants to release the value-added test score results for 12,000 teachers - revealing for parents and the public the student learning gains attributable to each instructor. News organizations have requested the data; the city is ready to comply. The city's United Federation of Teachers has challenged the release, and a judge will decide next month. I've spent many years looking carefully at such data. I know it can be incendiary; I know it has flaws.