False equivalence: the little-known English error that muddles the meaning of your text
A false equivalence is an error in writing that is both common and difficult to spot, even for native English speakers. It frequently occurs in the results section of science papers, where things such as methods, variables, metrics, and results are often compared. Despite its frequency, this grammar error is not often discussed, possibly because sentences with this error can often be understood from context. However, in academic writing, it’s important to be precise. In this article, I show you how to spot a false equivalence, and then I show you how to fix it.
Consider the following sentence, which is an example of a false equivalence:
The visibility of the target object in the image obtained by the proposed method is subsantially better than the conventional method.
The scenario behind the sentence is this: Our hypothetical authors have developed a new method that processes images so that the objects in the images are clearer. They have compared it with the conventional method for processing images, and they now want to tell us that their method works better than the conventional method because the visibility is better in the image processed by the proposed method. This situation can be illustrated as follows.

So why is the sentence a false equivalence? Let’s look at it again.
The visibility of the target object in the image obtained by the proposed method is subsantially better than the conventional method.
The visibility of one object can be compared with the visibility of another object, and methods can be compared with other methods, but this sentence does neither of those things. This sentence compares the “the visibility of the target object obtained by the proposed method” with “the conventional method.”
The situation is similar to the common English phrase “comparing apples with oranges,” which we use when two objects are too different to be compared meaningfully. A method isn’t a visibility, and it makes no sense to compare it with one.
To explicitly compare visibility with visibility, we must write something like the following.
The visibility of the target object in the image obtained using the proposed method is substantially better than the visibility of of the target object in the image obtained using the conventional method.
We’ve gotten rid of the false equivalence but gained another problem; the sentence is extremely repetitive and hard to follow. To solve this, we can use the pronoun “that” to replace the second occurence of “the visibility of of the target object in the image.”
The visibility of the target object in the image obtained using the proposed method is substantially better than that obtained using the conventional method.
This is why “that” is often added to papers; it fixes a false equivalence problem quickly and neatly. However, if deeper edits are acceptable, there are other alternatives; for instance, we can use the pronoun “it” and change the second phrase to reduce the repetition even further.
The visibility of the target object in the image obtained using the proposed method is substantially better than it is when the conventional method is used.
These are both good solutions. However, in this particular case, the readers already know that there are only two methods being compared. Hence, the fact that the results of the proposed method are being compared with the results of the conventional method does not explicity need to be repeated in every sentence. This enables an alternative solution that is easy to read, retains the meaning, and is concise.
The proposed method substantially improves the visibility of the target object in the image.
Problem solved.