JEFFREY BROWN: A major experiment is under way in American public education, one that could change what and how schools teach.

The NewsHour’s special correspondent for education, John Merrow, has the first of a two-part report on a new set of standards known as the Common Core.

JOHN MERROW: Today, Erin Garry's eighth grade English class is having a debate.

ERIN GARRY, The School for Global Leaders: Thirty seconds.

JOHN MERROW: And round one is about to begin.

ERIN GARRY: You guys can start.

MORE: Learning Matters met up with Commissioner of Education for New York State John King to talk about the new "Common Core" standards. STUDENT: Freedom of speech should mean what it's saying, freedom of speech. There shouldn't be limitations on freedom.

STUDENT: I disagree.

JOHN MERROW: Students in the center of the room argue their case.

STUDENT: But you have no proof.

ERIN GARRY: Thirty seconds.

JOHN MERROW: Team members on the sidelines offer support.

ERIN GARRY: They're passing notes saying, you should ask this follow-up question, or look at this page in your text so that you can reference this piece of evidence to support your ideas.

STUDENT: They have power, but we also have power.

JOHN MERROW: To prepare for the debate, the eighth graders have read several articles about freedom of speech.

STUDENT: You can't just say what you're saying because you feel, like, that's right. You need to have evidence about it.

STUDENT: You said that the government, that we have more power than the government.

JOHN MERROW: Teacher Erin Garry keeps score.

ERIN GARRY: Kids collect points for using certain discussion skills, according to the Common Core standards.

JOHN MERROW: The Common Core standards have been adopted by her state, New York, 44 other states and the District of Columbia. The new standards expect a lot more from students and teachers.

SHAEL POLAKOW-SURANSKY, New York City Chief Academic Officer: You have so many different skills that you're exploring in that one activity.

JOHN MERROW: Shael Polakow-Suransky is New York City's chief academic officer.

SHAEL POLAKOW-SURANSKY: You're getting kids to defend their ideas, to speak persuasively, to analyze the presentations that their peers are making, using evidence from nonfiction texts.

JOHN MERROW: Is that what the Common Core holds in the future, that kind of teaching?

SHAEL POLAKOW-SURANSKY: Yes. Critical thinking is the -- at the heart of this. Working in teams and collaborating is at the heart of this.

JOHN MERROW: So, before the Common Core, what was the situation?

SHAEL POLAKOW-SURANSKY: Every state had its own standards. If you went to Massachusetts, you had some pretty rigorous, tough standards -- Alabama or Louisiana, not so much.

ERIN GARRY: Students were learning different things in Florida from what they were learning in New York City from what they were learning in Nebraska, and even what they were learning in each school in New York City.

JOHN MERROW: To clear up the confusion, some governors and state superintendents developed a common set of standards, which states could choose to adopt or not. From the beginning, the Obama administration pushed the states to adopt them.

PRESIDENT BARACK OBAMA: We laid out a few key criteria and said, if you meet these tests, we will reward you by helping you reform your schools.

JOHN MERROW: The reward was significant: hundreds of millions of dollars to states that pledged to do what Washington wanted. States competed for a share of the $4.35 billion in what Washington calls Race to the Top.

MAN: We're nervous.

JOHN MERROW: Forty-six states and the District of Columbia presented ambitious plans.

RAYNE MARTIN, Recovery School District, Louisiana: Oh, we believe Louisiana is one of the top candidates for this. I mean, we have such exciting reform going on.

JOHN MERROW: Only a handful of states have actually won federal money, but most have fallen in line and adopted the Common Core.

The Common Core standards are only the what. They describe what students should know and be able to do at each grade level. They're not the how. How the standards are taught, what happens in classrooms, that's the curriculum.

Developing and selling curriculum materials is a billion-dollar business, but some states, including New York, are harnessing their own resources.

SHAEL POLAKOW-SURANSKY: We started by asking our teachers to build curriculum units, and the best ones go up on our Common Core library as models.

JOHN MERROW: Both New York City and New York state offer free Common Core lesson plans developed by teachers.

SHAEL POLAKOW-SURANSKY: Last October, one went up. It was so popular, in one day, there were 3,000 downloads.

JOHN MERROW: Suransky expects teachers to teach differently. New York City selected 35 schools where it's helping teachers make the transition.

Erin Garry teaches in one of them.

ERIN GARRY: Two minutes, one polish, one praise.

When we started implementing the Common Core at our school two years ago, I started giving students more responsibility within the classroom so that they can be responsible for their own learning.

STUDENT: Let's get the main idea about what we think about it, and then we can find evidence.

STUDENT: I think one of the most important ones was the last one.

JOHN MERROW: Jessie Startup has also modified her teaching.

JESSIE STARTUP, The School for Global Leaders: With mathematics, it used to be, this is how you do it. Here are your steps. If you don't do it that way, you're wrong.

Why you think this graph matches to one of the situations here.

Now the Common Core says, do it any way you want. Just be able to do it and justify your answer. So, students could draw a picture to figure out an answer, set up an equation, make a table. There's a variety of methods to do the same problem.

JOHN MERROW: Things may be changing in a few hundred classrooms, but New York City has 75,000 teachers. Brenda Cartagena has 13 years of teaching experience. She says many teachers, especially new ones, are feeling overwhelmed.

BRENDA CARTAGENA, The Courtlandt School: We were not given curriculums, and said this is what you guys are going to do. They just told us, this is the expectation, and you figure it out.

JOHN MERROW: How far are you to changing the teaching to line it up with the Common Core?

SHAEL POLAKOW-SURANSKY: I think we're about halfway there.

JOHN MERROW: Higher standards, innovative curriculum and changes in teaching are three aspects of what could be a sea change in America's schools. As challenging as they are, the final part, testing to find out if all of this is working, may be the highest hurdle of all.

When Kentucky tested Common Core skills last year, scores fell 30 percentile points.

Is this test a high-stakes test for you, the teacher?

ERIN GARRY: Yes. If my students bomb the test, that looks very, very bad for me.

And in first place with 66 points is team six.

JOHN MERROW: Schools, students and teachers will have this year and the next to transition to the Common Core. Serious testing begins in 2015.