As you review guidelines from journals you’re considering for manuscript submission, you may come across instructions to avoid using “passive voice” or “passive construction.” What does that mean, and why do journals want you to avoid it?
What is it?
When the “voice” of a sentence is passive, then the subject of the sentence is not doing the action. Instead, the action is being done to it.
Example: The car has been parked by the valet in the wrong parking space.
In this sentence, “car” is the subject, but the voice of the sentence is passive because the car is not doing the parking. Instead, the valet is performing the action.
Example: She was given the book by a friend.
In this sentence, the subject is “she,” but someone else (“a friend) is doing the action of giving a book.
In each sentence, the subject is not the “doer” of the action, but on the receiving end of it. We can make the voice of these sentences active, with the subject as the doer.
Example: The valet parked the car in the wrong space.
The above sentence is now in active voice, with the subject (the valet) performing the action (parked).
Example: Her friend gave her the book.
This sentence also is now in active voice, with the subject (friend) performing the action (gave).
In scientific writing, passive voice has been the norm for some time, but things are changing.
The reason so much scientific writing until recently has used the passive voice is largely that researchers were told ( passive voice) not to use “I” or “we” in writing. One rationale for prohibiting this use of the first person as the subject of a sentence was that it would distract readers from the science. Writers were to avoid drawing attention to themselves so that the science being described would be foremost.
Here is an example of this kind of writing from a historic paper, Watson and Crick’s 1953 report in Naturedescribing their discovery of the structure of DNA:
Example: “A structure for nucleic acid has already been proposed by Pauling and Corey.”
As you can see, the subject of the sentence is “structure,” yet “structure” is not the doer of the action (“proposed”). Pauling and Corey are the actors, the ones who proposed the structure.
Below is this sentence rewritten so that it is in active voice:
Example: “Pauling and Corey have already proposed a structure for nucleic acid.”
Here, the subject is “Pauling and Corey” and they are the actors, the doers, in the sentence.
Here is an example from the same paper, in this case a use of the passive voice to avoid using “We” in the sentence:
Example: “If it is assumed that the bases only occur in the structure in the most plausible tautomeric … it is found that only specific pairs of bases can bond together.”
Below is an example of an active voice version of this sentence:
Example: “If we assume that the bases only occur in the structure in the most plausible tautomeric … we find that only specific pairs of bases can bond together.”
As you can see, using active voice shortened the sentence slightly. Usually, active construction (or voice) does result in a shorter, more concise sentence.
Although the rare journal guideline still precludes authors from using first person when writing, most guidelines either specify a preference for active voice or make no mention of it at all. If you want to be sure that using “I” or “we” is OK, one way is to check the most recent published papers from the journal to see if those authors used the first person. That’s usually a good indication that doing so is acceptable. And that means you can write a lot of your paper in active voice.
The reason for the gradual switch from prohibiting first-person references in formal scientific writing to allowing them has to do with who is reading the publications. Internet availability and digital publication have increased accessibility of scientific papers for nonspecialists and even nonscientists. Publishers want writing that readers can understand, and very often, active voice results in writing that is more clear, accessible, and concise than when authors use passive voice.
That’s not to say that you should never, ever use passive voice. In fact, sometimes, it’s even preferable. Read below for some guidance about when to use active versus passive voice.
When active is preferable
If you can write a sentence with the subject as the doer, that sentence likely will be shorter and clearer for your reader. See the above example from the Watson and Crick Nature paper for how changing “it is” to “we” shortened the sentence. Here’s another example from that paper:
Example: “The novel feature of the structure is the manner in which the two chains are held together by the purine and pyrimidine bases.”
In that sentence, as originally written, the phrase in passive voice is “two chains are held together by the purine and pyrimidine bases.” The “two chains” are the subject of that phrase, and the action being done to them (passive) is “held together.”
The sentence below gives the same information, but using active voice, with the “bases” doing the action (“hold together”).
Example: “The novel feature of the structure is the manner in which the purine and pyrimidine bases hold the two chains together.”
The change from passive to active voice reduces the sentence length without harming the meaning or emphasis.
When passive is preferable
No scientific publication must be written entirely in active voice.
The above sentence itself is in passive voice, and that’s OK. It carries a little more power than the active version, which might read as follows:
“No researchers must write a scientific publication entirely in the active voice.”
In this case, as you can see, rewriting the original sentence in active voice actually made the sentence longer. The rewrite also shifts the element that had gotten the most emphasis by appearing at the beginning of the sentence. “Researchers” as a subject just isn’t as important as the topic of this article, which is “scientific publications” and active versus passive voice.
You can see another example from the Watson and Crick Nature paper:
Example: “Full details of the structure, including the conditions assumed in building it, together with a set of coordinates for the atoms, will be published elsewhere.”
You could rewrite this sentence as follows, in active voice:
“We will publish elsewhere the full details of the structure, including the conditions assumed in building it, together with a set of coordinates for the atoms.”
In doing so, however, you’d be placing “we” ahead of the “full details of the structure” of DNA, which is what is most important here. In addition, the rewrite makes the sentence just a little longer, which is usually not the desired outcome.
Ultimately, your scientific writing will likely contain a mix of sentences in passive and active voice. In fact, one more reason to occasionally introduce passive construction is to vary how your sentences are written. Variety in sentence construction is one key to good, readable writing.