Websites, books & tools
PIAAC is an every-10-year study of adult literacy, developed and organized by the Organization for Economic Cooperation and Development. The study seeks to determine how well adults are prepared to function in today’s society.
The U.S. Department of Education’s study is the most comprehensive, statistically reliable source on literacy in the United States.
William H. Dubay,,” Impact Information: Plain Language Services, 2005
Learn about U.S. literacy studies and research on readability and readability formulas from William H. Dubay, principal of Impact Information.
Smart Language (PDF)
William H. DuBay’s introduction to adult literacy surveys, research on readability and readability formulas.
Read the classics, the L.A. Sherman to the Flesch formulas, collected and curated by Impact Information’s William H. DuBay.
William H. DuBay’s introduction to the principles of plain language and guidelines for matching your text with the reading skill of the audience
Readability expert William H. DuBay’s blog