President Obama Just Ended No Child Left Behind. Here's the One Thing You Should Know.

Everyone hated it and Congress finally changed it.

President Barack Obama and a young student touch fingers during a January 2015 visit to a Lawrence, Kansas, Head Start provider.

President Barack Obama signed today the long-awaited overhaul of No Child Left Behind (NCLB), one of our country's most important education laws.

The Every Student Succeeds Act, which tackles several issues in George W. Bush's signature 2002 education law, was approved by large, bipartisan margins in the House and the Senate. This comes as a huge relief to many education advocates, parents, students, and lawmakers who have been trying to improve the increasingly unpopular NCLB for more than a decade.

While there are still countless unanswered questions around how exactly the new mandates will be implemented and funded in states and districts, one thing is clear: The new bill reflects a growing national consensus that schools can't be fixed through one-size-fits-all solutions coming from distant, federal officials.

As I wrote in my NCLB cheat sheet last week:

The original, well-intentioned No Child Left Behind law was intended to reduce stubborn race- and class-based achievement gaps. Instead, it created a system in which American kids take more standardized, mostly multiple-choice tests than their peers in any other industrialized nation. One high school senior in Florida told me that she took 15 standardized tests last year alone. By her own estimates, she spent about three months out of every high school year taking or preparing for multiple-choice tests.

Oh, and those achievement gaps haven't budged at all since NCLB went into effect. While racial gaps have narrowed slightly since 2001, they remain stubbornly large. The gaps in math and reading for African American and Latino students shrank far more dramatically before No Child Left Behind—when policies focused on equalizing funding and school integration, rather than on test scores. In the 1970s and '80s, the achievement gap between black and white 13-year-olds was cut roughly in half nationwide.

How is the new No Child Left Behind different, and will it improve learning and close racial and class disparities in achievement?

Short answer: The big change in the new bill is that it significantly reduces the power and the role of the federal government in grading, reforming, and punishing schools or teachers.  As I pointed out earlier:

The Every Student Succeeds Act keeps the biggest pieces of NCLB in place. Students are still required to take yearly tests in math and reading from third to eighth grade and once in high school. Schools still have to report the results of these tests by subgroups such as race, English-language proficiency, poverty, and special education. States will still be required to intervene in schools that are not meeting their goals. But they, not the federal government, will decide how to turn things around.

States, not the feds, will now be responsible for measuring students' academic progress. This means schools can ditch some standardized tests for things such as evaluations of student work and parent surveys. States and districts could theoretically use their limited money to pay local teachers—rather than education software companies—to measure kids' performance. And the federal government will no longer require using standardized-test scores to evaluate teachers, although states can chose to do that.

Will these changes improve learning and close kids' achievement gaps?

Short answer: Maybe. The new bill doesn't include all the pieces of the larger puzzle.

While these policy changes include many big steps in the right direction, including much-needed increases in funding for early childhood education, simply improving the criteria for grading schools and teachers won't necessarily lead to improved teaching and learning. Using more sophisticated ways to measure a patient's temperature doesn't automatically cure the root causes of a disease. Teachers, like doctors, need to continuously improve their craft and professional judgment so they can provide personalized teaching and address everyone's unique needs.

There are no easy answers, I wrote:

Research tells us that schools improve most when teachers are empowered. This includes reforms like increasing paid time for teachers to plan intellectually engaging lessons, letting them design their own assessments, and reflecting on student work to adjust their teaching. Successful, experienced teacher leaders need a variety of quantitative data, such as grades and attendance, and qualitative metrics like student engagement to find the root causes behind their pupils' achievement gaps.

Nationally, this sort of school-based professional development is difficult to sustain because American teachers have heavier teaching loads than educators in many other countries and little time for learning and leadership (three to five hours per week in most schools). Teachers in Finland, Singapore, and South Korea, by contrast, spend 15 to 25 hours each week working to improve their craft. In theory, Every Student Succeeds calls for districts to work directly with teachers and staff to design tailored classroom reform plans. But historically such mandates have not been fully funded and have been difficult to sustain.

Most importantly, classroom reforms face the biggest obstacles in schools with large numbers of low-income kids and students of color. In the past 10 years, the per-student funding gap between rich and poor schools has grown by 44 percent. Less funding means fewer qualified teachers, larger classes, and less time for teachers to plan, learn, and lead. It's hard to imagine making any significant progress in closing our achievement and opportunity gaps when these inequities are not addressed with the same systemic attention that's been devoted to standardized test taking.