Academic Writing: The Passive Voice: Why use it?

WHY use the passive voice in academic writing?

1. Often in academic writing, we don't want to focus on who is doing an action, but on who is receiving or experiencing the action. The passive voice is thus extremely useful in academic writing because it allows writers to highlight the most important participants or events within sentences by placing them at the beginning of the sentence.

Examples
In the following sentences, the passive construction is preferable because you want readers to focus on the result of an action rather than the person doing the action.

Active: Scientists classify glass as a solid.	The passive sentence focuses on how glass is classified, rather than on who classifies glass.
Passive: Glass is classified as a solid.

Active: Four members of the nursing staff observed the handwashing practices of staff during rostered shifts.	The passive sentence focuses on handwashing practices rather than on the four members of staff.
Passive: The handwashing practices of staff were observed by four members of the nursing staff during rostered shifts.

2. In addition, in academic writing sometimes it is obvious, irrelevant or repetitive to state who the 'doer' of the sentence is: thus the passive voice is a useful way to construct these types of sentences. It is also a way that the use of informal personal pronouns can be avoided; for example,

One type of work group, the semi-autonomous work group, is discussed in a section later in this chapter.	It is obvious that it is the author who will be doing the discussing.
The group was designed to last for only the lifetime of a particular project.	It is irrelevant to the reader here who did the designing.
The handwashing practices of staff were observed by 4 members of the nursing staff during rostered shifts. Handwashing, or failure to handwash, following patient contact was recorded. Leaving the area without handwashing was considered failure to wash.	The passive is used to avoid repeated reference to the known doer of the action (ie. the observers).
The number of seeds found in ant nests were counted.	The passive allows you to avoid using a personal pronoun (...by us).

3. Sometimes in academic writing it might be expedient to use the passive voice in order to avoid naming the 'doer' of an action so that the message of your text is less inflammatory; for example, read the following excerpt:

In this ideology the argument used to sustain the subjugation of women has largely rested on premises about biological difference - the biological differences between men and women have been used to legitimate hierarchical structures of social inequality. Women, because of their biological function as child bearers, have been traditionally confined to the domestic sphere and excluded from the world 'out there'.

The identity of the 'doer' in this text could be interpreted as society, the dominant social paradigm or males.

Text from: Jagtenberg, T. & D'Alton, P. (1989) Four dimensional social space: Class, gender, ethnicity and nature. Harper Row: Sydney.

Using the active voice in this passage would change the tone of the passage and create quite different message.

Passive voice

Active voice

In this ideology the argument used to sustain the subjugation of women has largely rested on premises about biological difference - society has used the biological differences between men and women to legitimate hierarchical structures of social inequality. Society has traditionally confined women, because of their biological function as child bearers, to the domestic sphere and excluded them from the world 'out there'.

Text from: Jagtenberg, T. & D'Alton, P. (1989) Four dimensional social space: Class, gender, ethnicity and nature. Harper Row: Sydney.

The text in the active voice focuses on the 'doers', that is society, rather than on women, the people acted on by the actions of others. The tone of the text is also much more political and accusatory:

'Society has ... confined women... and excluded them'

rather than descriptive and explanatory.