“Omit needless words.” So say William Strunk and E.B. White in their classic little book on good writing, The Elements of Style. Remembering this piece of advice, one of Strunk and White’s elementary principles of composition, will serve you well as you prepare to submit your latest scientific article for publication. There are many ways to pare your sentences to make “every word tell,”1 but let’s start with the expletive construction “it is known that.” Although expletive constructions have their place in good writing,2 their use often leads to unnecessary wordiness and can sometimes even confuse readers momentarily. Consider the following example:
This result indicated that the N and O atoms of the ligand were coordinated to the metal ion. It is known that the coordination mode of a carboxylate ion to a metal can be estimated from…
Some readers will pause at “It is known that,” momentarily misreading the expletive “it” as a pronoun referring to “metal ion,” the closest singular noun. You can eliminate this potential misreading, and prune four needless words, by revising to
This result indicated that the N and O atoms of the ligand were coordinated to the metal ion. The coordination mode of a carboxylate ion to a metal can be estimated from…
Eliminating the expletive “it” is especially important in sentences that also contain a pronoun “it.”3 In the following sentence, the first “it” refers to a previously mentioned absorption maximum:
Because it is located at 540 nm, it is not difficult to measure the reaction kinetics of the excited molecules.
Some readers will momentarily misread both instances of “it” as referring to the absorption maximum. To avoid this potential pitfall, consider one of the following alternatives:
Because it is located at 540 nm, measuring the reaction kinetics of the excited molecules is not difficult.
Because the absorption maximum is located at 540 nm, measuring the reaction kinetics of the excited molecules is not difficult.
Here are a few more example sentences, accompanied by suggested revisions in italics:
(1) It is known that most analogs with this general formula exhibit cross-resistance.
Most analogs with this general formula are known to exhibit cross-resistance.
Most analogs with this general formula exhibit cross-resistance.
(2) It is known that the two species are anionic and that they form an ion pair with an organic cation.
The two species are anionic, and they form an ion pair with an organic cation.
(3) It is known that Henry’s law constants have temperature dependence.
Henry’s law constants depend on temperature.
(4) It is known that the translational diffusion of the molecule is much faster than that predicted by the Stokes–Einstein equation.
The translational diffusion of the molecule is much faster than that predicted by the Stokes–Einstein equation.
You can also revise similarly for sentences like the following:
(5) It is generally thought that its therapeutic effect is triggered by…
Its therapeutic effect is generally thought to be triggered by…
(6) It should be noted that the former method has an advantage over the latter.
Note that the former method has an advantage over the latter.
The former method has an advantage over the latter.
(7) It is also reported that diffusion is exceptionally slow.
Diffusion is reported to be exceptionally slow.
Diffusion is exceptionally slow.
These simple revisions are especially handy when you need to trim your abstract to meet your target journal’s word-count requirements. So before you submit your next paper, do a quick search on “it is” and revise where appropriate, paying particular attention to whether “it” immediately follows a singular noun.
Notes
1Strunk, William, and E.B. White, The Elements of Style, 3d ed. (New York: Macmillan, 1979), p. 23.
2For some excellent examples of the usefulness of expletive constructions, see what Joseph M. Williams refers to as “it-shifts” in Style: Toward Clarity and Grace (Chicago: University of Chicago Press, 1990), p. 72.
3For a more-extensive discussion of this problem, and other problems with “it is,” see Bryan A. Garner, Garner’s Modern American Usage, 3d. ed. (Oxford: Oxford University Press, 2009), p. 484.