Plain Language Rewriting with AI

Plain language writing is a decades-old discipline with its own guidelines, formalized in the U.S. by the Plain Writing Act of 2010, which requires federal agencies to write clearly for the public. Traditional plain-language editing means replacing passive voice with active voice, shortening sentences, cutting unnecessary qualifiers, and defining or removing jargon -- work usually done by trained technical writers. A language model can propose a first pass when given constraints such as a target reading level, a maximum sentence length, and instructions to flag technical terms for definition. Its wording may be simpler yet still omit a condition, qualification, or responsible party, so the source remains controlling. The core risk, and the reason plain-language rewriting is not simply 'ask AI to simplify this,' is meaning drift: a rewrite can inadvertently soften a legal obligation, drop a conditional clause, or change a number's context (for example, turning 'up to 10 days' into 'within 10 days'). This is especially dangerous in legal, medical, and benefits contexts where a small wording shift changes what a reader is entitled to or required to do. Best practice pairs AI drafting with a domain expert or editor comparing the rewrite against the source line by line, and testing with actual readers when possible. A common misconception is that a lower Flesch-Kincaid reading-grade score alone proves a text is clear; readability formulas measure sentence and word length, not whether meaning was preserved or whether the structure helps comprehension.