The Common Core State Standards have been adopted by 45 states and the District of Columbia with the goal of better preparing the nation's students for college or a job. Despite their widespread adoption, many parents don't know what the standards are or whether their state has adopted them, according to an Associated Press-NORC Center for Public Affairs Research poll.

The new standards establish benchmarks for reading and math, replacing education goals that varied widely from state to state. Although the federal government was not involved in creating them, it has encouraged the state-led project. Supporters say the standards will better prepare students, while critics say they amount to a national curriculum for schools, preempting the states.

Overall, 52 percent of parents said they had heard "only a little" or "nothing at all" about the standards, according to the AP-NORC poll. About a quarter said they had heard "a lot" about them and 22 percent said they'd heard "a moderate amount."

About a third of parents said they were unsure whether the standards have been adopted where they live, according to the telephone poll of 1,025 parents, which was conducted June 21 through July 22.

A look at the learning standards and the issues surrounding them.

Q: What are the Common Core State Standards?

A: The standards spell out, grade by grade, the reading and math skills that students should have as they go from kindergarten through high school. For example, a first-grade reader should be able to use a story's pictures and details to describe its characters and then in second grade, be able to compare and contrast two versions of a story like Cinderella. In math, a first-grade student should be able to add and subtract, and in third grade do multiplication and division. The Common Core is not a day-by-day curriculum that dictates teachers' lessons.

Q: What's different from the old standards?

A: The new standards are considered more rigorous because they require students to think and reason more. The English standards rely on a more even mix of literary and informational texts, such as the Declaration of Independence. The math standards focus not only on the how, but the why, of problem-solving. As a result, standardized tests designed to track students' progress are more involved than the typical fill-in-the-bubble exams, translating to delays between test day and results, as well as higher costs to pay graders to reach short-answer responses.

Q: What states have not adopted these standards?

A: The only states that have not adopted the standards are Alaska, Texas, Nebraska and Virginia. Minnesota has adopted only the English standards.

Q: If so many states have adopted the Common Core standards, how come more parents don't know about them?

A: The standards are still fairly new. States only began adopting the standards in 2010 and not all have fully implemented them, so they may not have hit home yet for some, said Michael Resnick, associate executive director of the National School Boards Association. An August report from the Center on Education Policy at George Washington University found that many states have been phasing in the standards by grade or school district. Several states (nine in math and 10 in English) will begin implementing aligned curriculum in the upcoming school year or even later, the report said.

In a statement, American Federation of Teachers President Randi Weingarten said she thinks the lack of knowledge about the Common Core is because states and districts "have defined it through the lens of testing" without providing the right supports for the transition.

Q: Where did the standards come from and why were they needed?

A: The National Governors Association and Council of Chief State School Officers developed the standards with help from teachers, parents and experts. Before, individual states decided what students should know before they graduated from high school and that varied. The standards are seen as a set of uniform benchmarks to ensure that a high school graduate from any state will be ready to begin college without having to take remedial classes.