Editing Tip: 'Comprised' and 'Composed'

The usage of 'comprise' and 'compose' is currently a much-debated issue amongst grammarians. However, some scientific publishers, as well as many reviewers, are very picky about the technical usage of these terms, so it is important that you are aware of how to properly use them.

The vast majority of the time, comprise can be substituted for “is made up of,” but 1% of the time, comprise may mean “include.” The difference between these two usages is as follows:

• Primary usage: “The whole comprises (i.e., “is made up of”) all of the parts”
• Less-popular usage: “The whole comprises (i.e., “includes”) most of the parts” or “the whole comprises all of the parts that we know of right now.”
• Note: Please avoid using 'is comprised of,' which does not fit the definition of the word.

The complicating factor in this situation is the phrase is composed of. This phrase is frequently substituted for 'comprised,' but some publishers dislike it. Compose should be used when you list or state the parts first. The following examples help demonstrate the differences between 'compose' and 'comprise':

• “Graduate students compose the seminar.”
• "Seven steps compose our purification scheme."

But:

• “The seminar comprises graduate students.”
• "Our purification scheme comprises seven steps."

Why does this usage matter? Scientific writing aims to be clear and concise in relating precise information to a knowledgeable audience, and the phrase 'is composed of' is wordier, less precise, and a more passive way of saying 'comprised.' We hope that this tip will help you set your reviewers' and publishers' minds at ease by demonstrating a technical awareness of the proper usage of these terms. Please email us with any questions about this topic.