Sunday marks the 10th anniversary of No Child Left Behind (NCLB), passed by Congress in the summer of 2001 and signed by President George W. Bush on Jan. 8, 2002. It introduced a slew of changes to the federal role in education policy, required statewide testing in grades 3 through 8, established the Adequate Yearly Progress (AYP) system, outlined sanctions for schools labeled as failing under AYP and set a 2014 deadline for 100 percent of America's students to be proficient in math and reading.

In the following decade, NCLB has spurred monumental change in the education sector, experts agree, but has also earned its fair share of critics. In particular, the goal of 100 percent proficiency has been criticized as unrealistic, as has the tendency under the law to brand schools as "failing." The Obama administration has initiated a waiver program from AYP targets for states that commit to certain reforms, and a bill introduced in the U.S. Senate would discard the AYP system altogether, instead asking states to develop their own accountability metrics.

There has also been a transition of administrative responsibility and vision, from the leadership of Roderick Paige and Margaret Spellings during the Bush administration to current U.S. Secretary of Education Arne Duncan under President Barack Obama. As the 10th anniversary neared, officials and experts from the National Association of State Boards of Education (NASBE), the Council of Chief State School Officers (CCSSO), the Center for American Progress (CAP), a liberal think tank, and the Fordham Institute, a conservative education policy group, reflected on the similarities and differences in the two administrations' approach to the law, as well as its overall legacy.

All agreed that the breakdown of data under NCLB, which required states to break out achievement data by ethnic group and income level, was instrumental in illustrating the achievement gap that persists between disadvantaged students and their more affluent peers. The effort to collect data and target reform based on those numbers is probably the law's most important immediate impact, they agreed.

But the question of what do with that information begins to outline the differences between the policies of the Bush and Obama administrations, according to some experts. Brenda Welburn, executive director for NASBE, told Governing that the Obama administration "is not as interested in punitive action." For example, Obama and Duncan have advocated for reauthorization bills that would scrap the AYP system, which had initially been used to label schools as "failing" or "passing." Failing schools could be subject to interventions or a loss of federal funding under the current law.

Through Race To The Top and the NCLB waivers, Obama has focused more on the reform side of the equation, Welburn said. She did note that while the waiver program ostensibly offers states more flexibility, "there is still some rigidity to it," she said, because states must consign to reforms dictated by the federal government. Thus far, 11 states have applied for NCLB waivers, although more are expected.

While the Bush administration, which named NCLB after the idea of aiding disadvantaged students, deserves praise for that focus and breakdown of data, the Obama administration has gone to greater lengths to help schools improve, said Cynthia Brown, vice president for education policy at CAP. The data showed the significant struggles of some students, but many schools were left unsure of what to do about it, Brown explained, and had only AYP targets to guide them. With an infusion of more than $4 billion to states committed to certain reforms under the Race To The Top program, as well as greater use of the School Improvement Fund, the Obama administration has provided schools with the money to figure out how to improve their students' performance, Brown said. "It lets them try new things."

Chris Minnich, membership director at CCSSO, also said that the current leadership has been more proactive in providing "turnaround models" through its funding of various reform efforts. "Data is only part of the point," Minnich said. "We have to be able to say: 'Here's the data. Here's what we can do with it.'" He added, though, that states saw a gradual and slight shift since Obama took office in 2009, rather than a fundamental overhaul. "From a state perspective, we didn't see a large difference," he said, observing that "both administrations had an affinity for the law" and emphasized the need to improve.

Mike Petrilli, executive vice president at the Fordham Institute, who served in the U.S. Department of Education's Office of Innovation and Improvement under Paige, agreed. "Both administrations bought into the centrist, school-reform philosophy that says our schools are not doing nearly as well as they could be," he said. "Schools and districts are not going to improve without a push from the federal government."

Under both administrations, the Education Department was forced to adapt as it became clear that parts of the law weren't working: Bush oversaw a shift in policies for special education students and English language learners, while Obama has initiated a waiver program and has pushed for a complete reauthorization, although Petrilli asserted that he viewed the waivers as "not legal" because they offer relief from NCLB requirements in exchange for commitment to specific reforms.

Petrilli also credited the "consequential accountability" of the law with an increase in student achievement, pointing to the National Assessment of Education Progress (NAEP) results. Average scores in fourth-grade math have increased from 226 (out of 500) in 2000, before the law was passed, to 241 in 2011. Average scores in eighth-grade math have jumped from 273 to 284 over the same period. African-American and Hispanic students have particularly made significant gains. It is noteworthy, however, that those numbers have begun to plateau in the last few years, again raising the question of what to do next.

All sides concluded that NCLB, despite its flaws, has irrevocably altered the landscape of public education and its impact will be felt for years.

"Almost everything about education policy right now that's moving forward in the states is because we starting highlighting the data" under NCLB, CCSSO's Minnich said. "It's changed the conversation so much."