National Center for Education Statistics (2012). The Nation's Report Card: Vocabulary Results From the 2009 and 2011 NAEP Reading Assessments (NCES 2013–452). Institute of Education Sciences, U.S. Department of Education, Washington, D.C.
A National Assessment of Educational Progress report reveals gaps in vocabulary achievement among students from families of different income levels and students from different racial and ethnic backgrounds. While the assessment only recently began measuring vocabulary, officials say results already show connections between vocabulary skills and reading comprehension.