Choosing the Appropriate Verb Voice-Active or Passive

You can use either the active or the passive voice when you describe the procedure used in your project. Examples of both voices are given in the following box. Notice that the formation of the passive voice requires the be auxiliary + the past participle of a verb.

Your decision whether to use the active or passive voice in procedural statements should be made with the following considerations:
1. The passive voice is conventionally used to describe procedure in order to depersonalize the information. The passive construction allows you to omit the agent (usually "I" or "we"), placing the emphasis on the procedure and how it was done.

EXAMPLE A: For reasons related to personal safety, the test
facility was constructed (by us) in a remote area 4 miles from the main road.

EXAMPLE B: Tests were conducted (by me) with four different types of reactors.

However, your professor or editor may specifically ask you not to use the passive voice because he or she prefers a more personal style with frequent use of the pronouns "I" or "we."

2. In addition to questions of style, your choice of the active or passive voice should place old information near the beginning of the sentence and new information at the end. The old information is italicized in each sentence in example C.

EXAMPLE C: The four reactors we tested in the work reported here all contained a platinum catalyst (ACTIVE).

Each reactor-catalyst configuration will be described separately (PASSIVE).

The quartz reactors were manufactured by the Wm. A. Sales Company of Wheeling, Illinois (PASSIVE).