What the passive actually does
The passive moves the receiver of the action into the subject position and makes the actor optional. That is a tool, not a defect. It lets you keep the same topic at the front of consecutive sentences, which is one of the strongest things you can do for readability, and it lets you omit an actor nobody cares about.
Compare two versions of the same methods passage. Active with a named agent: “A technician incubated the samples for 24 hours, and then another technician centrifuged them.” Passive: “The samples were incubated for 24 hours and then centrifuged.” The passive version is shorter, keeps the samples in view throughout, and drops information no reader wants. It is the better sentence.
The reason the passive has such a bad reputation is that it is also the easiest way to write a sentence with no one in it. That failure mode is real and worth hunting. But treating every passive as an error means rewriting good sentences to satisfy a rule that was never about grammar in the first place.
Where the passive earns its place
Methods sections are the clearest case. The procedure is the subject of interest, the performer is either you or a member of your team, and repeating that in every sentence adds nothing. “Interviews were transcribed verbatim and coded independently by two researchers” tells a reader everything relevant, and the one actor that does matter — two independent coders — is named precisely because it matters.
The second case is topic continuity. If a paragraph is about a particular gene, a particular text, or a particular policy, starting each sentence with that thing keeps the reader oriented. Forcing the active voice would rotate the subject to whoever acted on it and scatter the paragraph’s focus.
The third is when the actor is genuinely unknown or unimportant. “The manuscript was copied in the late fourteenth century” is not evasive; nobody knows who held the pen. Demanding an active version here would require inventing an agent.
- Procedures where the performer is you or your team and adds nothing.
- Paragraphs that need the same topic in subject position sentence after sentence.
- Historical or physical events with no known or relevant agent.
Where the passive hides something
The problem case is the agentless passive attached to a judgment. “It was determined that the outlier should be removed” conceals a methodological decision behind a construction with no one in it. A reader cannot assess a choice whose maker is invisible, and reviewers read this pattern as evasion whether or not it was meant that way.
The same applies to unattributed belief. “It is widely accepted that early intervention is effective” raises the question of who accepts it, and often stands in for a citation the writer did not have. Replacing it with “Three recent reviews conclude that early intervention is effective (…)” fixes both the voice and the evidence in one move.
A useful test: add “by whom?” after the sentence. If the question has an answer that a reader would want, the passive is hiding something. If the answer is “nobody relevant,” the passive is fine and you can move on.
Converting a passive that is not pulling its weight
Conversion is mechanical once you have decided to do it. Identify the hidden actor, put it in subject position, and turn the participle back into a finite verb. “A significant reduction in error rates was observed following training” becomes “Error rates fell after training.” Eleven words to six, and the verb now describes what happened rather than what someone noticed.
Watch for the pairing of passive and nominalization, because it doubles the damage. “The application of the coding scheme was undertaken by two reviewers” contains a passive, a nominalization, and a semantically empty verb. “Two reviewers applied the coding scheme” recovers all of it.
One caution: do not convert a passive if the active version forces you to name an agent you have no basis for naming. Precision outranks voice. If you do not know who decided something, say what is known and leave the rest, rather than manufacturing a subject to satisfy a style preference.
