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Following the publication of Carl Heneghan’s blog on strategies for great teaching in evidence based medicine, he invited Jeff Aronson to write a companion piece on strategies for good writing. In the first of three parts Jeff suggests three general principles.

What qualifies me to write an article about good writing?

  • I have published many papers and blogs, in many different forms. That doesn’t prove or guarantee that I am a good writer, or that I can tell others how to write, but it may help. You would expect a sports coach to have played at the level that those being coached hope to achieve.
  • I have read widely, both fiction and non-fiction. That doesn’t necessarily make me a better writer, but again it may help.
  • I have collaborated with others in devising definitions of technical terms in pharmacovigilance; some have been adopted internationally.
  • Colleagues often seek my advice on linguistic matters and send me their papers for comments, which they seem to welcome.
  • Some at least have expressed appreciation of what I write. Presumably others have just kept quiet.

I certainly have opinions on the subject. And I’m not alone; in this area many have opinions, often stated with utter certainty, but little hard evidence, and the spectrum of opinions is wide.

At one end are pedantic prescriptivists, who insist that there is only one way of doing anything and that all other ways are wrong. At the other end are extreme libertarians, who insist that almost anything goes, provided it’s generally used; they sometimes bend over backwards to justify their position. Somewhere in the middle, but closer to the latter than the former, are the descriptivists, who just tell it as it is. In other words, they document how people use the language, rarely commenting on rights or wrongs or even citing personal preferences. My position is somewhere between the descriptivists and the libertarians, modified by the practicalities of communication. I am not (I think) extreme and I believe that extreme views should be disregarded—that’s a libertarian’s prescriptivist view!

My suggestions represent my own opinions. Others, at both ends of the spectrum, may disagree, possibly vigorously. But any methods anyone recommends should be regarded not as rules, but as preferences.

Let’s start with a writer I admire.

Richard Asher

Richard Asher was a physician, reputedly an excellent practitioner. But he is best remembered for his elegant essays and his accounts of two clinical conditions, Munchausen’s syndrome and myxoedematous madness

In September 1961 Asher wrote a piece for the Nurses’ Magazine of the Central Middlesex Hospital, where he worked. It was titled “Aren’t I Lucky? I Can Write!” Here’s an extract:

“Have you ever tried writing? No? I thought you could not have done. It is so laborious and tedious that authors often despair of getting their ideas on to paper at all. It is hard enough to find ideas worth writing, but harder still to put them into words worth reading.”

Can writing be as hard as he suggested, or by implication as soul-destroying? It is certainly laborious, and perhaps should be. But tedious? I don’t find it so, although others may. But reflect on those last three words: “words worth reading”.



Readability—words worth reading

The Oxford English Dictionary defines “readable”, referring to written text, as “clear, comprehensible; easy, enjoyable, or interesting to read; written in a lively or attractive style”. It defines “readability as “the quality … of being easy to understand and enjoyable to read”.

Readability actually has three facets: how easy it is to read the text in the typeface in which it is printed, how interesting the subject matter is, and how easy it is to understand it.

I shall not deal here with subject matter. Some topics will be of interest to some, others to others. Some will be important, some trivial; both types need careful attention. Nor shall I deal with typography. Here I am concerned with how easy it is to understand the text. It is in that sense that the term “readability” is often used—words worth reading. It would be better called comprehensibility—words worth understanding.

However, there are no clear criteria by which writing that produces words worth reading can be judged. Many readability indexes have been designed to measure this. But their methods are simplistic, based on nothing more than estimates of word difficulty (the numbers of characters or syllables per word) and sentence difficulty (the numbers of words per sentence). The underlying assumption is that shorter words and shorter sentences are easier to read and understand. For example, the formula for the Flesch Reading Ease score, calculated to a surprising degree of precision, is:

206.835 – (1.015 x ASL) – (84.6 x ASW)

where ASL = the average sentence length and ASW = the average number of syllables per word.

I have entered a range of texts into a readability calculator (Table 1). Some are from my own writings, some co-authored, and some are from others who have a reputation for clear writing.

According to these measures, what I write is of variable readability. For example, the Flesch Reading Ease score grades my writing as difficult or very difficult to read, but other measures rate it as comprehensible by, in some cases, 12-year-olds. Furthermore, the indices rate a full Cochrane abstract as easier to read than the corresponding plain language summary. Most telling, perhaps, are the assessments of the first page of Ernest Hemingway’s short novel The Old Man and the Sea, whose text is over 80% monosyllabic; the data in the table speak for themselves.

If the Gunning Fog Index, for example, assesses Hemingway, written for a general audience, as “hard to read”, what am I to make of the same assessment of my own writing, written for specialists?

But variability is not the only problem with the readability indices. They also fail to take account of important factors, all hard to quantify, such as rhythm, punctuation, alliteration, the avoidance of clichés, and the use of striking metaphors and humour. Above all, they do not consider overall tone and coherence, two major aspects of readability.

Table 1. Readability scores for a range of texts using seven different indices; reading ages are in years, converted in many cases from US school grades




Readability index
Automated Readability Index Coleman-Liau Index Flesch-Kincaid Grade Level Linsear Write Formula Simple Measure of Gobbledygook (SMOG) Index Flesch Reading Ease score Gunning Fog Index
This blog 13–15 15–16 14–15 16–17 14–15 Fairly difficult Hard
Another blog* 17–18 14–15 17–18 22 + 16–17 Fairly difficult Hard
A BMJ editorial 22 + 21–22 21–22 21–22 21–22 Difficult Difficult
A Lancet book review 21–22 15–16 21–22 22 + 16–17 Difficult Hard
Cochrane SR: Abstract† 12–14 16–17 16–17 13–14 15–16 Difficult Hard
Cochrane SR: Plain Language Summary† 22 + 22 years + 21–22 21–22 21–22 Very difficult Difficult
The Old Man and the Sea 13–15 11–12 12–13 17–18 10–11 Easy Hard
Ernest Gowers, Plain Words 14–15 14–15 16–17 21–22 15–16 Fairly difficult Hard
Charles Kay Ogden, General Basic English Dictionary 22 + 12–13 22 + 22 + 15–16 Difficult Difficult

*Described by a colleague in a tweet as “accessibly erudite”


The spoken and the written word differ. Anyone who has ever tried to transcribe ordinary conversation knows that. A lecture on the other hand may be delivered in language that is more like writing. Conversely, conversational writing can sometimes be effective, as long as it’s not too breezy, and sometimes it’s preferable to write more formally. But avoid excessive formality, which the late medical writer and broadcaster Michael O’Donnell called “decorated municipal gothic”. He first described it in World Medicine in 1971 and defined it, in A Sceptic’s Medical Dictionary (1997), as “a prose style that evolves when writers eschew simple words that might express their ideas in a neat and palatable form and use instead language they believe adds dignity, scientific worth, or even grandeur to their utterances.”

Literary tone is sometimes called “voice”, and different authors cultivate different voices. An author of fiction may adopt different voices for different characters. In any piece of scientific writing a single voice is preferable, but you might vary the voice from article to article, depending on the seriousness or triviality of the topic, perhaps more lecture-like for the former, more conversational for the latter. You might also write differently for different audiences. But no-one can advise you how to achieve this. It’s largely subjective.

The complement of voice is ear. A good ear will help you tell whether your own voice is clear and help you in judging other people’s voices. You can cultivate it by reading.


By “coherence” I mean choosing appropriate words to say what you want to say unambiguously, phrasing them in fluent rhythmical sentences, appropriately punctuated, and linking the sentences and paragraphs in logical order.

Three general principles

  1. Find a simple tone of expression, or voice, that feels natural to you; don’t overdo it, hoping to impress, or thinking that it’s expected.
  2. Try to write coherently, in such a way that the reader will never be held up at any point, wondering what you mean, or at the end be in doubt about what you intended to impart.
  3. Try to follow well-worn grammatical guidelines that no-one will complain about, but break the rules when it feels right.

The last principle is based on the idea that is unnecessary to annoy your prescriptivist readers when you can write clearly without contravening what they regard as rules. Consider the sentence “Every writer needs to pay attention to the style in which he writes.” At one time that would have passed without comment, but today it would prompt a charge of male sexism. Some might write “Every writer needs to pay attention to the style in which she writes”, or “Every writer needs to pay attention to the style in which he or she writes”, avoiding the main charge. Alternatively, the problem could be avoided by writing “Every writer needs to pay attention to the style in which they write.” But by bending over backwards in those ways, in each case the emphasis of the sentence moves from the writer to the pronouns, he, she, and they, diverting the reader’s attention. A simple solution would be to make the subject of the sentence plural: “All writers need to pay attention to the style in which they write.” Or make it even simpler: “Writers should pay attention to style.” Short, simple, unimpeachably grammatical, clear, and offensive to no-one.

There is no easy way to learn how to write well. You have to write again and again, subject what you write to critical examination by those whose views you respect, and take to heart the comments they make. If they spot stumbling blocks, remove them. If they spot what they think are errors, think about them and correct them; even if they are preferences rather than errors, others may regard them as errors and criticize you. But sometimes, if you feel justified, just take a chance.

In the second blog in this series I shall discuss some simple guidelines.