Readability

Readability is the ease with which a reader can understand written text. It depends on text features such as vocabulary difficulty, sentence length and structure, paragraphing, cohesion, and typography, as well as reader characteristics including prior knowledge, reading skill, and motivation. Readability is a proxy for comprehension rather than a direct measure, but it guides writers, educators, and designers in tailoring material to intended audiences.

Readability metrics seek to quantify text difficulty. Common formulas include Flesch Reading Ease, Flesch-Kincaid Grade Level, SMOG, Gunning Fog, and Coleman-Liau. They typically estimate the required reading ability from sentence length and word or character complexity, providing a score or grade level. While useful for general prose, these metrics have limitations and are most informative when applied within appropriate contexts.

Applications include educational material design, editorial and publishing planning, web content and user experience, technical writing, and government communications. They help set target audiences, compare texts, and monitor accessibility alongside other usability and comprehension assessments.

Limitations and criticisms note that readability scores do not capture content quality, organization, domain knowledge, motivation, or cultural relevance. They can misrepresent the difficulty of specialized texts and may encourage oversimplification. They should be complemented by user testing and plain language guidelines.

To improve readability, writers can shorten sentences, use more common vocabulary, favor active voice, and present information with clear structure, headings, and signposts. Clear typography, adequate spacing, and legible fonts also aid readability. Plain-language practices emphasize audience focus, explicit definitions, and concise expression.