Sunday marked an anniversary that few educators celebrated. On Jan. 8, 2002, President George W. Bush signed the No Child Left Behind Act into law, setting off a decade of test-driven school reform.

The landmark law mandated annual testing in reading and mathematics with the ultimate goal of all students reaching a “proficient” level by the 2013-14 school year. Schools had to reach escalating target scores to prove “adequate yearly progress” or risk a failing label.

Districts had to sort out scores by students’ race, ethnicity and other characteristics, so schools could no longer mask low-performing students.

Patterning the complex law on reforms from his home state of Texas, Bush said, “The fundamental principle of this bill is that every child can learn, we expect every child to learn, and you must show us whether or not every child is learning.”

Thus began a frenzy of standardized testing that turned many of America’s classrooms into drill-and-kill laboratories in which anything not on the test fell to the wayside.

Schools that reported jumps in their annual test scores earned headlines, parties and visits from beaming governors. Those that did not suffered failing labels and falling morale.

Over the past decade, there has been a steady increase in percentage of schools each year that did not make AYP. In the latest report, 2010-11, roughly half of the nation’s schools failed to reach their goals. But because states could set their own baseline for proficiency, there are wide variations from one state to the next in how well schools are meeting their targets.

“The percentage of schools not making AYP varies from a low of 11 percent in Wisconsin to a high of 90 percent in Florida,” said Brian Stecher, associate director, RAND Education, and co-author, “How Federal Education Policy Under the Elementary and Secondary Education Act Can Support States in School Improvement.”

The pressure on schools to meet testing targets fueled a cheating scandal in Atlanta that is the nation’s largest ever, implicating nearly 200 educators and costing taxpayers millions in investigatory and legal fees.

And there is evidence that the cheating that besmirched Atlanta’s reputation also occurred elsewhere in the country.

Indeed, some of the impressive results in Houston schools — the so-called Texas miracle — on which Bush modeled No Child turned out later to be an illusion, in part because schools dramatically undercounted their dropouts.

There have been treatises written on where No Child went off track. But there is also evidence of some successes. Researchers Thomas Dee of Swarthmore College and Brian Jacob of the University of Michigan found strong evidence that math achievement improved in the earlier grades as a result of the law. The improvements were concentrated in the earlier grades, in grade 4 math scores and mostly among Hispanic and low-income students. (However, they found no improvement to reading scores.)

No Child forced districts to pay attention to children they had historically written off: low-income and minority students and those with learning disabilities. But being armed with a clearer sense of which students were struggling didn’t always lead to effective solutions.

“Having the data out there is necessary, but not sufficient,” said Charles Barone, who, as top education adviser to House Education Committee member George Miller, helped write No Child. “A healthy system will respond by fixing the system. An unhealthy system will tend to respond by blaming individuals like teachers.”

“The government stepped in because there has been a vacuum created by the colleges and universities that train teachers, by unions that negotiate bargaining agreements that put junior teachers in the toughest classes and by administrators who look the other way,” said Barone, now director of federal policy at Democrats for Education Reform.

“One thing that No Child Left Behind did,” he said, “was shine a light on problems that people were aware of but didn’t want to acknowledge.”