GWEN IFILL: Congress is on the verge of finally approving a rewrite of the education law known as No Child Left Behind. The Senate is expected to pass it easily tomorrow. The House did so last week, and the president is expected to sign it. It will give states more control over public schools, but still requires annual student testing.

Tests have long been the subject of heated debate, especially those tied to the new and more ambitious Common Core standards. This fall, results are coming in for the first time, and in many places, they have been disappointing.

That includes New Jersey, where many parents have been concerned about excessive testing.

John Tulenko of Education Week has the story.

JOHN TULENKO: The Common Core standards, adopted by most states five years ago, raised the expectations for students and launched a massive effort to create new curriculum and train teachers to teach it. Now the results of Common Core tests are coming in, and they're feeling like a bucket of cold water.

DAVID HESPE, Education Commissioner, New Jersey: The scores will show that we have great challenges ahead

JOHN TULENKO: New Jersey's education commissioner, David Hespe, recently shared results from his state. In English language arts, fewer than half of students were proficient, and, in math, only about a third, a steep decline in proficiency rates compared to the old state test. The numbers are similar in many other states.

Commissioner Hespe asked the public not to panic.

DAVID HESPE: It's the first year of an initial test. We should be humble. We should be patient. We should take our time to review all this information.

JOHN TULENKO: To help make sense of all this, we turned to a testing expert, Rutgers University professor Drew Gitomer.

So, first question for you is, what's it going to mean for New Jersey?

DREW GITOMER, Rutgers University: Well, when you raise the standards, as the Common Core has been trying to do, you're judging it against a higher level of expectations for students. And there may have been a false sense of proficiency under the previous state testing regime.

WOMAN: This is how specific the data is.

JOHN TULENKO: Officials in New Jersey and other states are counting on data from the new online tests, including PARCC and Smarter Balanced, to show teachers the way forward.

DAVID HESPE: We can use the information we're going to be getting from PARCC to help us close curriculum and instruction gaps in individual classrooms throughout the state of New Jersey. Our prior test could not do that. This test can.

JOHN TULENKO: But experts like Gitomer aren't so sure that even highly specialized test results will make a difference.

DREW GITOMER: Simply by providing that information and assuming that teachers and administrative leaders have the capacity to take that information and translate it into better practice seems to be — I'm skeptical of that.

JOHN TULENKO: Why? Because it's been tried before. Millions of students have already been taking, on average, eight state standardized tests per year.

And for more than 20 years, the federal government's been giving a national test, NAEP, that just sounded the alarm again about disappointing results in math and reading, especially for low-income and some minority students. But performance on these tests has proven very difficult to move.

Why should we think it's going to be different this time around?

DREW GITOMER: That's a very good question. This goes back to the old cliche that you don't fatten up a pig by weighing it all the time.

JOHN TULENKO: Even President Obama recently said public schools test too much.

PRESIDENT BARACK OBAMA: Learning is about so much more than just filling in the right bubble.

JOHN TULENKO: No more than 2 percent of the school year, the president now says, should be devoted to standardized testing. So, if tests aren't likely to change things, what will?

DREW GITOMER: I think we want to spend more of our effort in high-quality curricula, not on finer and finer diagnosis of students.

JOHN TULENKO: But Common Core's about more than tests. States used millions of their own money, and federal funds, to train teachers and develop curriculum to help students meet the new standards. And New Jersey wants to do more.

DAVID HESPE: We have to look at supports for students, tiered interventions for students. We need to look at expanding things like early childhood programs.

JOHN TULENKO: But it's not clear how the state will pay for all this. Federal grants to support the Common Core have run out.

And New Jersey's own general aid, which keeps schools running day in, day out, is about what it was in 2009. Similar conditions in many other states may limit their options too.

DREW GITOMER: With the Common Core, I think there was a lot of well-intentioned folks who were trying to raise the bar and use it as an impetus for improving instruction.

But I do think, if you look at what has happened in a variety of expensive initiatives, including No Child Left Behind, the emphasis has largely been on the testing, and not on what to do once we get the test results.

JOHN TULENKO: States say they will continue their efforts to improve instruction and hope to see better results next time around.

One state, Ohio, has taken a short cut. It's simply lowered the bar by setting its own more modest pass rates. And, not surprisingly, its students seem to be doing better.

I'm John Tulenko of Education Week reporting for the PBS NewsHour.

PBS NewsHour education coverage is part of American Graduate: Let's Make it Happen, a public media initiative made possible by the Corporation for Public Broadcasting.