The abstract is perhaps the most important section of your research paper. Apart from the title, it may be the only part of the paper anyone reads. Whether they read further depends in part on how good an impression your abstract makes.
The abstract may also be the only part of your paper that has a word limit. Most word limits specify a maximum of between 250 and 300 words, and some journals require that abstracts be as short as 150 words. Writing a great abstract is almost an art—but writing an abstract that meets word limits is, well, a science.
Why do journals impose word limits on abstracts?
There are several reasons your abstract needs to be short and concise. Journals want readers to buy your article, and they want other researchers to cite your study in their own articles. More citations means a higher impact factor for the journal. The best way to sell your study is to grab the reader’s attention with a great title and abstract. Finally, there is the issue of space. Journals want your abstract to fit on half a page so that a reader won’t have to scroll to read all of it.
When it comes to abstracts, less is more. Only essential information needs to be presented. A short, powerful abstract will draw readers into your research and help the journal attract more readers and receive more citations. The trick is how to trim your abstract to get under the word limit. Here are some time- and researcher-tested ways to pull that off.
Omit needless hedge words and adverbs.
In their acclaimed guide to English writing, The Elements of Style, William Strunk, Jr, and E. B. White teach the key to meeting abstract word limits: Omit needless words. Many writers, especially academic writers, pepper their writing with words that simply don’t need to be there.
A “hedge” is a word or phrase you use when you are concerned about making a claim instead of stating a fact. It’s always a good idea to be careful, especially in academic writing, but many authors use hedge words when they don’t need to. Among the most overused hedge words are the verbs “seem” and “appear.” In the examples below, you’ll see why taking away the hedge words does not alter the meaning.
Hedge: Maroney syndrome seems to impair quality of life.
No Hedge: Maroney syndrome impairs quality of life.
Hedge: Ibuprofen appears to diminish pain in most patients.
No Hedge: Ibuprofen diminishes pain in most patients.
In both pairs, the first and second sentences have essentially the same meaning, except that the second sentence omits the hedge word. Notice how the second examples are more powerful and straightforward without this extra verbiage.
Cutting out needless adverbs is another easy way to limit the number of words in an abstract.
With needless adverbs: We slowly and carefully dissected the vagus nerve.
Without needless adverbs: We dissected the vagus nerve.
By definition, “dissection” is slow and careful (or should be!). Removing the needless adverbs “slowly” and “carefully’ leaves you with a sentence with the same meaning and three fewer words. Same your adverbs for situations in which they truly impact the meaning or have an impact on the reader or interpretation.
Remove awkward and unnecessary transitions.
Conjunctive adverbs are better known as “transition terms,” and although they can be very usually in creating structure and flow within the body of a paper, in the abstract they are often redundant or even incorrectly used. Among the more commonly used conjunctive adverbs are: however, moreover, therefore, furthermore, additionally, and thus.
The conjunction “moreover” is perhaps the most commonly used needless adverb in scientific papers. Some writers use it because they believe it makes them sound more “academic.” Others use it because they may know that it’s a grammatical faux-pas to start a sentence with the conjunction “And.” Nevertheless, “moreover” can virtually always be removed from a sentence without altering the meaning. Watch what happens when we remove the word “moreover from these sentences.
With a transition: Moreover, we dissected the vagus nerve.
Without a transition: We dissected the vagus nerve.
In the instance above, “moreover” does not really make sense as a transition term. Even other transition terms (furthermore, therefore, in addition, etc.) would be somewhat unnecessary when discussing how the study or experiment was performed.
With a transition: Furthermore, patients with Boney-Maroney syndrome are likely to experience hot flashes and fatigue.
Without a transition: Patients with Boney-Maroney syndrome are likely to experience hot flashes and fatigue.
Note that these two sentences have exactly the same meaning with and without the transition term “furthermore.” These transitions can be much more useful in the longer sections of the paper’s body, especially in the Introduction and Discussion/Conclusion sections.
Use the active voice instead of the passive voice.
One way to shorten your abstract is to apply a rule you might have learned in primary school: use active voice instead of passive voice. In active voice constructions, the subject carries the action. In passive voice, the subject is acted upon, usually by an unnamed actor. Scientists seem to be in love with the passive voice, as it can be found in many papers, simply adding to the word count and making the write less engaging. Because of this longstanding convention, many believe it makes them sound more “scientific.” Others shun active voice because they feel as though it is too personal. That is a shame. Your sentences will often sound more convincing and powerful in active voice, as the following examples demonstrate:
Passive voice: Pituitary cells were grown in dishes that had been subjected to irradiation (12 words).
Active voice: We grew pituitary cells in irradiated dishes (7 words).
Passive voice: Three-hundred and forty-five patients who had undergone ovariectomy at our institution were enrolled in the present study (17 words).
Active voice: We enrolled 345 patients whom we had ovariectomized (eight words).
Remember, studies don’t conduct themselves; scientists conduct studies. Avoid using the passive voice in the abstract—save it for the Methods section!
Do not include statistical methods or findings in the abstract.
Most scientific articles include statistics. Usually, the statistical methods are described in detail in the Methods section of a paper. But many authors feel compelled for some reason to mention statistics in the abstract, perhaps to get the details out first. But unless your paper is primarily about statistics, it is best to keep statistics out of the abstract and stick to language that expresses the most important use and findings of the study. Not only do statistics add to your word count, but they also interrupt the flow of your argument. You certainly do not need to tell the reader what statistical tests you used or the version of the statistics program you used—that is what the Methods section is for. And never go into detail about EXACTLY which findings your study yielded—that is what the Results section is for.
Consent, approval, and other stuff that doesn’t belong in an abstract
Some authors place information about patient consent and institutional review board approval in the abstract. Whereas this information is indeed essential, it is not necessary to put it in the abstract. Like statistics, consent and approval statements interrupt the flow of your argument. Readers expect to find information about consent and approval in the Methods section. Leaving this out of your abstract will certainly free up your space to describe the importance of your study.
Word limits are not targets
Keep in mind that a limit of 250 words does not mean that you should attempt to come as close as possible to the limit. The best abstracts include all essential information well before reaching word limit. Use the above tips to help you create a leaner, tighter abstract that will hook readers and entice them to read your full study.