Developing and Evaluating the Fidelity and Understandability of Plain Language Summaries of Position Statements.

The American Association on Intellectual and Developmental Disabilities (AAIDD) and The Arc of the United States (The Arc) have a long history of taking jointly held positions on matters of public policy that affect people with intellectual and developmental disabilities (IDD). This article describes the methods used to develop and evaluate the understandability and fidelity of written plain language summaries of the organizations' joint position statements for an audience of people with IDD who read. Implications for adapting source material for nonreading audiences are discussed.