What plain language is, and what it is not
Plain language is writing whose intended readers can find what they need, understand what they find and use it, so it is judged by what readers can do with a text rather than by how short its words are. It is not speech written down, a vocabulary for children, dumbing down or a mechanical shortening of words and sentences. It applies to professional readers as much as to lay ones, and it stops before simplifying patronises the reader or loses the meaning.
What plain language is
Plain language, also called plain English, is communication the audience can understand the first time they read or hear it. It is writing in clear, concise language that is easy to read and understand. No one technique defines it: plain language is defined by results, a text that is easy to read, understand and use. Plain language is one aspect of readability, how easily a text can be read and understood.
The Center for Plain Language, as quoted in 2010, defines a communication as in plain language if its audience can quickly and easily find what they need, understand what they find, and act appropriately on that understanding. The definition the Plain Language Association InterNational was due to adopt in 2015, and that the ISO plain-language standard published in 2023 puts at its centre, is that a communication is in plain language if its 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. Under that definition plain language is not a specific way of wording, organising or designing content but an approach to those processes, aimed at conveying the writer's message in a way that fits the needs of the target readers.
Garner, a former editor of Black's Law Dictionary, defines plain language as the idiomatic and grammatical use of language that most effectively presents ideas to the reader: grammar provides the common ground for weaving words together in a way that makes sense to readers of a language, and idiom draws on the stylistic and aesthetic preferences that help readers connect with content. The ideas are not new: in the first century Quintilian advocated simplicity with style, so that messages are conveyed with accuracy and elegance.
The ISO plain-language standard
The standard, ISO 24495-1:2023, Plain language — Part 1: Governing principles and guidelines, is organised around four principles, each elaborated in its own subchapter with detailed guidelines and a small number of examples:
- Readers get what they need (relevant): identify the readers; identify the readers' purpose; identify the context in which readers will read the document; select the document type or types; select content that readers need.
- Readers can easily find what they need (findable): structure the document for readers; use information design techniques that enable readers to find information; use headings to help readers predict what comes next; keep supplementary information separate.
- Readers can easily understand what they find (understandable): choose familiar words; write clear sentences; write concise sentences; write clear and concise paragraphs; consider including images and multimedia; project a respectful tone; ensure that the document is cohesive.
- Readers can easily use the information (usable): evaluate the document continually as it is developed; evaluate the document further with readers; continue to evaluate readers' use of the document.
Around the principles and guidelines sit a foreword, an introduction, the scope, normative references, terms and definitions, and two annexes, an overview of the principles and guidelines and a sample checklist. Under the standard, plain language focuses on how successfully readers can use the document rather than on mechanical measures such as readability formulas.
Medical writers know the usefulness of standards from the ICH's standards for drug development, and the plain-language standard provides advantages of its own:
- Interoperability: a shared understanding of what constitutes plain language, a basis for discussion and for its use in special domains, and a common standard into which components developed in those domains can be integrated.
- Clarity and consistency: clear guidance on developing texts that users understand easily, which reduces ambiguity and makes communication more reliable.
- Cost efficiency and compliance: help in streamlining the process of writing in plain language and so reducing costs, with compliance with the guidelines serving as a measure against which writers and readers can evaluate plain-language texts and their efficiency.
- Collaboration and development: a common framework in which practitioners work, which will speed development and exchange across languages.
- Portability: the transfer of texts across environments and languages, since compliant documents can be translated more easily without major modifications.
Why plain language matters
There is ample evidence across many domains that writing in plain language saves time or money or both for readers and organisations. Communication in plain language is generally more effective and produces better outcomes than traditional writing, readers in many contexts prefer it, and its use fosters the building of trust. Translating is usually more efficient for plain-language documents.
Everyone benefits from text that is clearly constructed and easy to understand, and from health information that is clearly communicated. For a reader whose first language is not English, whose general literacy is not high, who is elderly and perhaps in the first stages of a neurodegenerative disease, who is frightened by anything medical or who has just been given devastating news by a doctor, clear text and clear messaging are not just nice to have but crucial, and can literally be the difference between life and death.
Adapting technical content for lay readers saves readers time and effort in understanding, and so supports learning, decision-making and inclusivity. It carries important findings to a broader audience, including the general public, educators, policymakers and specialists outside the field. Juries are increasingly called on to weigh highly technical evidence, such as chemical, financial, forensic and AI-related evidence, and much legislation includes technical content that lawmakers need to understand and evaluate. Lay versions of specialised content can also make academic research more accessible to researchers in related fields who might not have encountered, understood or paid attention to the paper in its original publication. Translating technical text into lay language is key to democratising access to knowledge, promoting a wider understanding of complex aspects of the modern world, and fostering an inclusive environment where information is accessible to all.
On one view of what health information needs, information generated in a way its user cannot understand is of no value, so plain language has to be built into the generation of information. That means not only simple language but representing information in non-textual ways, for people whose first language is not the one the information was generated in and for people who process information graphically much better than textually. The information has to be usable by the end user, not a data dump or a scouring of the available articles suddenly consolidated into a meta-analysis. On the same view, all of this relates to trust: a patient who does not understand the information does not even approach the portal of trust.
One patient living with eosinophilic granulomatosis with polyangiitis describes the first response to a diagnosis with a complex name as asking what that is in human language. On that patient's account, clarity for patients means understanding things in their own language, since much of the information available is in English, and in relation to their own context.
What plain language is not
It is not writing as one speaks: in 1753 the Comte de Buffon wrote that those who write as they speak, even though they may speak well, write badly. Speech is different from writing and is often not plain at all: people rarely speak spontaneously in plain language or simple structures, and speech cannot be gone back over and edited, so plain English in writing is not achieved by emulating spoken English.
It is not a simple lowest-common-denominator language used all the time, nor is it all about monosyllabic words or writing in a way children can understand. It means using words the writer expects the audience to understand, formulating sentences and paragraphs to make the text easy to understand, and making the text as concise as possible.
It is not dumbing down, a criticism often levelled at those who advocate plain language. A UK Department of Health sentence, "The provision of adequate dietary energy to ensure normal growth and development should be a principal determinant of the diets of children under five years of age", can be rewritten for parents as "To ensure that children under five grow and develop normally, one of the main things they need is calorie-rich food": the original is good English, but it needs rewriting when its purpose and audience change, and that is clearing up rather than dumbing down.
Complex scientific and medical subjects do not require dense, hard-to-follow writing, nor do they require the text to be dumbed down to be readable. Writers who genuinely care about their readers and their subject work hard to make their writing clear, engaging, accurate and easy to understand, and they edit by looking at several key features that serve as flags for poor writing. Writers can improve their ability to communicate complex topics with clear writing that is easily understood on a first read.
It is not a mechanical shortening: converting text into plain language is not as simple as reducing the size of the words and shortening the sentences; if it were, someone would long ago have written a program to do it. It takes knowledge and experience to process the information and then produce it in a simpler form while keeping the messaging and tone intact.
Nor is it a trade against accuracy: in the view of the US Centers for Disease Control and Prevention's senior advisor for health literacy and the Plain Writing Act in 2013, professionals who prepare materials for lay audiences often invoke a false trade-off between accuracy and ease of understanding, which excludes some people from information they need to protect and improve their health. She held that medical communication specialists have a professional responsibility to make it easier for audiences to find, understand and, most important, use health, medical and science information.
Plain language for professional readers as well as lay ones
Plain-language principles apply to all informative writing, whether readers possess specialist knowledge or not, because readers at all levels of expertise welcome and deserve clarity. Medical writers should always strive to write plain English, whatever the context. In language terms they produce four basic types of text: texts for regulatory purposes and medical communications texts, and within each, texts aimed at professional and at lay readers, with scientific publications either counted as medical communications or treated as a separate group subject to the same principles. Different styles of plain English are required for these groups.
Some medical writers, even experienced ones, argue that certain documents, such as those destined for regulatory agencies, must be written in awkward, excessively technical language because of supposed rules or standards; one journal editor holds that this is a dogma with no rules or guidelines to justify it. In some hands, medical English has become understandable only to the writer and a few experts. A regulator, too, would want to avoid the lost time and headaches of deciphering bad writing.
Writing for peers, a writer can assume they know or can understand the technical terms that are a normal part of the lexicon, and can still do them a favour by keeping long sentences and awkward passive constructions to a minimum. A writer should never assume that only fellow professionals will read the text, or that all its readers share the writer's first language.
User testing of the educational materials supplied with European risk management plans and US risk evaluation and mitigation strategy documents, aimed at health professionals and at patients, made it very clear that writing for health professionals really is the same as writing for patients: both want plain, clear and easy-to-access information.
Writing simply should be practised in whatever type of communication is being developed, from detailed reports to simple emails, because everyone is busy and no one wants to wade through lines of superfluous text.
Plain language is essential in many circumstances, especially for ensuring that science, instructions or methodology are understood. It is easy to slip from plain language into gobbledygook. In one writer's view, a bit of flowery language, and even gobbledygook, works well in some communications to create a particular feel or ambience.
Where simplifying goes too far
Avoiding long, involved sentences must not lead to a text so simplified that the reader feels patronised. When preparing texts for patients it is easy to slip into what is almost baby talk, such as tummy instead of stomach or abdomen, and the writer must look out for this and avoid it.
Patients are unlikely to be medical experts, so the language of a text for them needs to be straightforward and free of medical and technical jargon. But the information should not be oversimplified so that it becomes inaccurate or unclear; to ensure accuracy of meaning, over-simplification should be avoided. Stating that "the tablets may affect your bowels", for example, could mean that the tablets may cause diarrhoea, constipation, wind or something else.
Evaluation studies on the X-Plain patient education materials show that users who have more experience, or who are highly health literate, are not offended by simplified content.