From the story here:
In math American teens rank 20 points lower than the international average—and 12 points lower than their own 2012 average. ... The trouble is that the standards, [Jon] Star [of Harvard] said, were designed with elementary and middle school students in mind: "It's not surprising that some of these interventions have had minimal to no effect in high school—because that's not really who they were intending to effect."
