The Importance of Defining Terms

Words have meanings. (Photo credit: porah/stock.xchng)

Words have meanings. This is the basis of language and shouldn’t surprise anyone. Yet people often use one word when they mean another — and this significantly weakens many attempts to communicate about scientific topics.

There are two issues here: first, make sure you use technical terms correctly; second, define those terms. This second point is significant, because even if you are using a technical term correctly, you should not assume that your reader will understand precisely what you meant.

This is particularly true for scientific terms that people think they know and understand. This was driven home recently when I read a blog post by David Shiffman on fifteen important shark conservation and management terms, which includes definitions of words like “extinction” and “population.”

I asked Shiffman why he wrote the post, and he noted that a lot of people are simply using these terms incorrectly. For example, extinction is “the complete disappearance of a species from the Earth.” But Shiffman is seeing the word extinction used to refer to sharks that are being fished out in specific locations but are still in existence elsewhere. Seeing local populations of a species disappear is still bad, of course, but it has very different legal (and biological) implications from the disappearance of a species globally.

The word population is another good example. Technically, it refers to a group of individuals of a species living in a particular area; it does not refer to all of the members of a species. So, if a population reaches zero individuals, the word extinction does not apply. It is only when a species reaches zero individuals that it is extinct. These are incredibly important distinctions, but they are distinctions that a nonexpert reader likely would not pick up on.

“The conservation movement will be extremely limited in the successes they can accomplish if they use legal and technical terms incorrectly in petitions and public comments,” Shiffman said. As an example, Shiffman pointed to a petition seeking to declare sharks an endangered species. The lack of precision in that petition poses a problem because there are more than 500 species of sharks, many of which don’t meet the definition of an endangered species.

I’m using sharks to illustrate the need for precise use of language, but this issue extends to every discipline. Defining your terms may seem tedious, and you don’t want to be patronizing when communicating with your readers, but you don’t want to be misleading either. Always use terms correctly, and find an elegant way to define the technical ones.