Previously in this series on how to write a scientific paper: ten tips for revising your first draft
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After you have finished with your first pass and are now happy with the overall shape of things, it is time to polish the micro-level structure of words, sentences, and paragraphs. Once again, your overall goal should be simplicity, clarity, and readability. You can achieve this goal by cutting out everything that is not necessary. Condense and straighten your sentences so that they are short, to-the-point, and easy to follow. When editing your sentences, pay attention to these points:
- Ensure that each sentence in a paragraph belongs to that paragraph: the first sentence defines the topic of the paragraph, and the rest stick to the topic. If a sentence goes off in a tangential direction, delete it or move it elsewhere; if the paragraph is long and its topic appears to change on the way, split the paragraph into two or more.
- Check that your sentences follow one another logically and that there are no jarring, abrupt changes in direction. Tie your sentences together with transitional words. Begin your sentences by addressing the words or concepts that finished the previous sentence, or use conjunctions that refer to the previous sentence (however, in addition, to the contrary, and so on).
- Check sentence length; aim at short, precise sentences. Try to make every sentence shorter by rephrasing the idea using fewer words and cutting out words that do no work. Those lazy words include repetitions and unnecessary adverbs and adjectives—almost always, if you remove “very”, your sentence will be tighter. Also look out for wordy expressions involving the passive voice or nominalizations of perfectly good verbs (see below). Tighten your sentences, remove redundancy. Rejoice for every word that you cut!
If your sentence still feels too long after tightening, look for ways of splitting it. Long sentences are taxing to read because the reader has to hold a great number of words in her short-term memory: about 25 words is already at the limit. You do not need to count words for spotting sentences that are too long, though. You can spot those sentences visually (if a sentence spans several lines, it is too long) or, better, by reading your text aloud. Wherever you stumble or run out of breath, you have a problem.
- Make meaning early in the sentence, and keep your subject and verb close. If the first words tell who does what, it is easier to decipher the rest of the sentence. If the main point of the sentence becomes clear in the beginning, even wordy sentences can be comprehensible. But if the meaning of your sentence is only unlocked by its 27th word, the long and winding road there will be littered with the remains of readers who have perished from utter mental exhaustion.
- Use active voice and avoid the passive (for exceptions, read on). There is a long tradition in the scientific literature to use the passive voice, probably because the passive voice sounds more distanced and impersonal—somehow more “academic”. But when anyway writing about abstract concepts, there is no reason for making them any more abstract, impersonal, or distant! So it is time to get rid of this tradition: avoid the passive wherever you can.
How to spot the passive when editing? Easy—if your sentence ends with the actor (“by X”) or if you can insert “by zombies” to the end of the sentence without violating grammar. Whenever you spot a passive sentence, try to rephrase it and activate the verb. “X influences Y” is better and shorter than “Y is influenced by X”. If you use active verbs, your sentences will be stronger, shorter and more readable.
You do not need to always use the active voice, though. There are times when the passive voice works better; some concepts and elements sound out of place if made actors. It is OK to use the passive voice when the researcher wants to remove herself (or other researchers) out of the picture. Common examples include “it has been experimentally confirmed that” or “it has been argued that” (in particular if you disagree with the argument but do not want to name the culprits). Also, if you want to stress whatever is being acted upon, that is, the receiver (or victim) of action, use the passive voice. “The climate is influenced by greenhouse gases” stresses the word “climate”, whereas “greenhouse gases influence the climate” focuses more on the greenhouse gases.
- Avoid nominalizations—turning verbs into nouns. Nominalizations take the life out of perfectly good verbs. And because what was once a happy, active verb has now been shrunk into a sad noun that just sits there, doing nothing, a replacement verb is required. These are usually clunkier and duller, like “carry out”, “perform”, “conduct”, or plain “to be”. In addition to sounding like company-speak, these verbs make your sentences longer than they need to be.
When you happen to come across nominalizations, rescue and release the original verb from captivity and let it roam free again! Say “we compared” instead of “we performed a comparison”, say “we examined” instead of “we conducted an examination”, and say “we analysed” instead of “we carried out an analysis”.
How to spot a nominalised verb? Nouns that have a captive verb inside, waiting to escape its torment, often sound like French or Latin—they end with “-ion”, “-ence”, or ”-ment”. Adjectives can also be nominalized into nouns, and there can even be chains where “to differ” becomes “different” that becomes “difference”. The difference between these forms is that “X differs from Y” is much simpler than “there is a difference between X and Y”. And shorter by 21 characters!
- Avoid words that end in “-ive”—those are adjectives that have a verb inside, struggling to get out. Release the verb! Instead of “X is indicative of Y”, say “X indicates that Y.”
- Comb your text for clunky expressions that are simpler and shorter in plain English. Plain “because” is much more effective than “as a consequence of” or “due to the fact that”. “Although” works better than “despite the fact that.” Do not say “for the purpose of” when you can simply say “to”, or “for”. Search for “in order to” in your text; replace with “to”. Search for “such as” in your text; delete these words and rewrite the sentence without them and it will sound better. For more examples—and a convenient search-and-replace list—see http://plainenglish.co.uk/files/alternative.pdf.
- Search for “moreover” in your text. Delete it. Rewrite the sentence using perfectly good simple words – “besides”, “in addition”, “also”– that are common in everyday speech. No-one says “moreover” anywhere else than in scientific journals; people probably use this word only because they saw someone else use it.
- Avoid using jargon and complicated words as a blanket, to feel secure. Excessive amounts of jargon often result from thinking that for something to sound academic and scientific, it has to be complicated, full of expressions that no-one uses in everyday speech. This is wrong. The more simple and the more clear your writing is, the more authority it has. It is more difficult to trust a writer who hides her point behind a facade of long sentences and complicated words; these feel like smoke and mirrors, tricks to hide the absence of depth. You do not appear more intelligent if your writing is too complex, to the contrary of what many seem to believe. However, if you use words that everyone can understand to explain complicated issues, Richard Feynman would be proud of you. Science is difficult enough as it is—do not make it any more complicated with your writing.
- Bonus tip: learn from the masters. Get The Elements of Style by Strunk & White, and do as the masters tell you. Your readers will thank you for it.