Passive voice can be employed to emphasize the action over the actor by placing more focus on the receiver of the action rather than the doer. This is achieved by structuring the sentence in a way that the subject of the sentence undergoes the action rather than performs it. This shift in focus helps highlight the action itself and its importance, rather than the individual carrying it out.

In scientific or procedural writing, the use of passive voice is helpful for several reasons:

1. Objectivity: By de-emphasizing the doer of the action, passive voice can create a sense of objectivity in the writing. This is important in scientific writing where the focus is on presenting facts and results rather than individual actions.

2. Clarity: Passive voice can help in making complex procedures or processes easier to understand by focusing on the action or the result. It can streamline the writing by putting the emphasis on what was done rather than who did it.

3. Generalization: Passive voice can also be useful in generalizing processes or procedures, as it shifts the attention from specific individuals to the action itself. This can be particularly beneficial when describing methods or techniques that are applicable regardless of who is performing them.

By highlighting the process or result rather than the individual performing the action, passive voice can contribute to a more precise and impactful presentation of information in scientific or procedural writing.