Revised naturalization test explained

On October 1, 2008, USCIS started administering a new naturalization test to applicants for US citizenship. Anybody who filed their N-400 (the form used to apply for naturalization) after that date must take the new test. Anyone who applied before that date and is interviewed before 10/1/09 can take the old test if they prefer. Anyone who is interviewed after 10/1/09, regardless of when they filed the N-400, must take the new test.

The USCIS website states that:

The content of the new civics test has been completely revised. The content now follows a basic U.S. history and government curriculum and focuses on fundamental principles within three categories: American government, American history, and integrated civics. The test is still administered orally and an applicant must still answer six out of 10 questions correctly to pass the civics test.

Full details of the new test, including extensive study materials, are here.