The Perils of Metrics

True progress is hard; it is always easier to move the goalposts than to score more goals.  Human beings are very good at rationalization and self-deception, so adjustments made in ambiguous or complicated situations for varied motivations are not always obviously directly aimed at shifting the reference in order to inflate the metric.

On the other hand, some are more transparent than others:  "Los Angeles initially required that students earn at least a C in those classes, but the number of students on track to graduate plummeted. Now grades of D or higher are accepted."

While I'm not an unquestioning fan of Arne Duncan, in this case he gets the big picture exactly right:

"But `the goal is not just high school graduation,' Arne Duncan, the departing secretary of education, said in a telephone interview. `The goal is being truly college and career ready.'"

http://www.nytimes.com/2015/12/27/us/as-graduation-rates-rise-experts-fear-standards-have-fallen.html