Glossary · 3 · Understanding
Plain language
Also known as: Plain English, Plain writing, Clear communication
German: klare Sprache
According to ISO 24495-1:2023, plain language is communication in which wording, structure and design are so clear that the intended readers can easily find what they need, understand what they find and use that information.
- Applied cognitive psychology
- Understanding
- Standards
In one sentence
Plain language is communication whose wording, structure and design let intended readers find, understand and use information (ISO 24495-1:2023).
Example
A start-up chapter is revised to ISO 24495-1: readers are identified (line operators, some with German as second language), the chapter is reorganized by task, terms match the HMI, and a test with operators shows they can find and complete each step.
Rests on
- Working memory and Cognitive load theory: short, direct sentences, familiar words and clear structure reduce the load of decoding so that readers can attend to the content.
- Situation model and Inference (reading comprehension): plain language makes the relations readers need explicit instead of leaving them to inference.
- Information foraging: the "find" part of the definition rests on how readers search and scan.
How it applies
- The standard: ISO 24495-1:2023 (ISO/TC 37) sets four governing principles: readers get what they need (relevant), can easily find it (findable), can easily understand it (understandable) and can easily use it (usable), each with guidelines, and treats evaluation with readers as part of the process.
- Law and policy: In the United States, the Plain Writing Act of 2010 (Public Law 111-274) requires federal agencies to use plain writing in documents they issue to the public.
- Technical documentation: Identify readers and their tasks, structure by task, use the terms of the product and the HMI consistently, put one action in a step and test with readers. Plain language complements standards for information for use; it does not replace them.
Plain language vs. controlled language vs. easy-to-read language
- Controlled language (for example Simplified Technical English) restricts vocabulary and grammar by rules, often for translation and machine processing. Plain language is defined by the outcome for readers, not by a rule set.
- Easy-to-read language (in German Leichte Sprache) is a separate, more strongly simplified form for people with reading difficulties or learning disabilities, with its own rules and testing by target readers. Plain language addresses the general intended readership.
Limits
- The standard gives principles and guidelines; it does not set a readability score, and applying it does not make a document compliant with product legislation.
- Plainness never justifies omitting required content or safety-related information; what must be said follows from the risk assessment and the applicable law, plain language only governs how it is said.