|1 Change and continuity in American democracy: ideas, institutions, practices, and controversies.
2 The gathering of interactions of peoples, cultures, and ideas.
3 Economic and technological changes and their relation to society, ideas, and the environment.
4 The changing role of America in the world.
NOTE: The numbers in this table represent the post-scaling counts of items.
SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2006 U.S. History Assessment.