YOUR first-grader might know all about the Three Bears, but does she know the three states of matter? And does the name Simon Bolivar ring as familiar as Tinkerbell to your second-grader?It wasn't enough that E.D. Hirsch Jr.'s popular but controversial books made Americans uncomfortable about their level of cultural literacy. Now he's refined his science, and he's out to teach the next generation. In the first installments of his "Core Knowledge" series of books for grade schoolers, the University of Virginia professor and education reformer has just published "What Your First Grader Needs to Know," and "What Your Second-Grader Needs to Know." The books are the result of several years of consultation and consensus-building among 2,000 teachers and scholars about a specific sequence of core knowledge - or core curriculum - that American children should, at a minimum, learn. Professor Hirsch's theory of cultural literacy is based on the idea that literacy is more than a skill - like reading or ciphering - but that it requires specific information. It's not how you learn, but what you learn that is basic to a good education, argues Hirsch. Emphasis on skills rather than information leaves children - especially those from disadvantaged homes - with a deficit of cultural knowledge, an incomplete foundation for building future knowledge, he says. "The curriculum that now exists in the public school is essentially a set of vague guidelines sometimes given by the state, sometimes by the district, and they are usually in terms of process - a child shall learn how to read and how to write. How these guidelines are implemented is up to the individual teacher," says Hirsch. "Using the same guidelines, you cannot depend on any particular first-grader getting the same content as another first-grader in the same school. It's an incorrect picture that we have some sort of systematic building-block curriculum, because the emphasis is on process rather than content." The books, says Hirsch, are an attempt to lay down some continuity of curriculum, to spark education reform that would get Americans to decide on a core of knowledge children need. Their content - fundamentals from nursery rhymes to world history and basic geometry - is already being integrated into the curriculum of several schools in Florida that use different methods to impart the knowledge. Hirsch's casual dress and easy manner in an interview here is foil to any images his prescripts might conjure of a culture snob peering down his nose at the intellectually unwashed. Having been battered politically both from the left and right over his ideas, he says he feels like a "lonely voice." But he notes that internationally, core curriculum is state of the art: Every Western European and Asian nation where students regularly outperform American students use a core-knowledge sequence in elementary schools. "One of the very frustrating things about my experience over the last four or five years is that the conversation about what I wrote instantly went to the ideological and political," he says. "Aren't you trying to impose middle-classdom on people who don't want to be middle class?" he says he is often asked. "I would say the aim of a just society would be to make everybody middle class," he says, adding that race has nothing to do with it, because there is a middle class among all ethnicities. "Given economic justice and equal opportunity, people have nice houses, they have a good education, they want the best for their children. They begin to sound very much like what we think of as middle class. I'm puzzled to see what's wrong with middle class," he says. "One of the aims of this project and core curriculum in general would be to give underprivileged, disadvantaged children some of the same advantages, some of the same knowledge that people who come from literate or privileged homes have access to - a sort of substitution for the middle-class home." Asked for a specific example of how core curriculum is important and why it is not just a memorization of facts, he offers this explanation: A third-grade teacher tries to discuss South American geography or history. She should be able to assume that all students were taught in the first and second grade the basic concepts of the solar system, Earth's relation to the sun, and what the equator is. "But suppose what tropical means is not registering," he says. "Then as a teacher, I'm going to pause and talk about summer and winter and longitude and the Earth's path around the sun. What's happening is a lot of backtracking and bringing up to snuff a part of a class that hasn't got the background knowledge they need [to build on]. That cuts effective class time quite a lot."