One-Minute Writing Improvements: Correcting Comparisons
A rule to instantly improve your writing: “Compared to” (or “compared with”) never replaces “than” without a sentence rewrite.
This construct is common in academic work, and misuse is understandable. Often the sentence does make a comparison. However, using “compared to” in place of “than” inevitably leads you to compare the wrong things.
Take this example:
*Patients who took Drug A experienced greater improvement in symptoms compared to those who took Drug B.
The placement of “compared to” in this sentence suggests the reader should compare improvement to patients, when the comparison intended is patients who took Drug A and patients who took Drug B. We naturally want a participle like “compared” to modify the closest noun, in this case, “improvement.” Placing the items compared at the opposite ends of the sentence breaks this grammatical link and makes your reader work harder—never a good thing.
Two fixes are available:
- Patients who took Drug A experienced greater improvement in symptoms than those who took Drug B.
- Compared to patients who took Drug B, patients who took Drug A experienced greater improvement in symptoms.
Notice “compared to” now modifies “patients” in the second example.
Both “than” and “compared to” work to compare things, but must be treated differently. Improve your writing by not using them interchangeably.