This won't make MisEducation Minnesota very happy. A recent NBER report says that not just testing matters to increase student performance, but testing with consequences.

In looking state-by-state, Hanushek and Raymond find that the introduction of accountability systems leads to higher achievement growth than would have occurred without accountability. But simply reporting results of tests has a minimal impact on performance. The systems are much more effective if poor educational results have adverse consequences for the schools, thus supporting the contested provisions of NCLB that impose sanctions on failing schools.

Interestingly, though, testing-with-consequences increased the black-white achievement gap because the improvement in black test scores is less than the improvement in white test scores. The report also shows that blacks are hurt by higher minority concentration in their schools. From their paper:

The finding of differential effects of accountability raises a clear policy dilemma. A prime reason for the U.S. federal government to require each state to develop a test based accountability system involved raising the achievement of all students, particularly those at the bottom. It has done that, but not at the same rate across groups. We conclude from this that additional policies are needed to deal with the multiple objectives. Again, as is frequently the case, a single policy cannot effectively work for two different objectives � raising overall student performance and providing more equal outcomes across groups.