Case Study 1: Rescuing a Methods Paragraph, Sentence by Sentence

A worked repair. Watch each error get named and fixed in turn — this is the before/after engine running at full length.

Dr. Lena Foss, an early-career principal investigator you'll follow through Part III, is finishing the methods section of her first paper. The science is sound; the writing is not. Here is a paragraph from her draft, lightly edited and used with permission as a composite example (the errors are typical of real first drafts, not any one person's):

"After preparing the samples, the centrifuge was run at 12,000 rpm for ten minutes. The supernatant, which contained the dissolved proteins that we needed for the assay, were then transferred to clean tubes, this step is critical because contamination at this stage invalidates the results. There are three measurements that each tube undergoes, they include absorbance, fluorescence, and we record the temperature. Neither the calibration standards nor the blank was prepared fresh, this introduced a source of error."

Four sentences. At least eight errors. Let's walk them.

Sentence 1 — the dangling modifier

"After preparing the samples, the centrifuge was run at 12,000 rpm for ten minutes."

The opening phrase After preparing the samples needs a human doer. The grammatical subject is the centrifuge — so the sentence claims the centrifuge prepared the samples. Dangling modifier.

Two fixes, and the choice matters for a methods section:

✅ A (active, supply actor): "After preparing the samples, we ran the centrifuge at 12,000 rpm for ten minutes." ✅ B (passive, rewrite modifier): "Following sample preparation, the centrifuge was run at 12,000 rpm for ten minutes."

Many journals still prefer the impersonal passive in methods, so Lena may choose B. Both are correct; the original was not. Note the lesson from §6.2: dangling modifiers and passive voice are friends, because passive hides the actor the modifier is hunting for.

Sentence 2 — three errors in one

"The supernatant, which contained the dissolved proteins that we needed for the assay, were then transferred to clean tubes, this step is critical because contamination at this stage invalidates the results."

Error 1 — subject–verb disagreement. The subject is supernatant (singular). Strip the intervening clause — which contained the dissolved proteins that we needed for the assay — and the skeleton is "The supernatant … were transferred," exposing the disagreement. The plural proteins, sitting closest to the verb, pulled Lena's ear to were. Fix: was.

Error 2 — comma splice. …transferred to clean tubes, this step is critical… joins two complete sentences with a comma. Fix: period or subordination.

Error 3 — orphan this (×2, mild). This step is actually fine — it has a noun (step). But the second this stage is also nouned. Lena got these right; the splice was the real problem. (A good reminder that not every this is an orphan — only the bare ones are.)

✅ Fixed: "The supernatant, which contained the dissolved proteins needed for the assay, was then transferred to clean tubes. This step is critical, because contamination at this stage invalidates the results."

(We also trimmed that we needed → needed — a small Chapter 3 concision cut riding along.)

Sentence 3 — splice plus faulty parallelism

"There are three measurements that each tube undergoes, they include absorbance, fluorescence, and we record the temperature."

Error 1 — expletive padding. There are three measurements that… buries the real subject. Promote it.

Error 2 — comma splice. …each tube undergoes, they include… — two independent clauses, one comma.

Error 3 — faulty parallelism. The series is absorbance (noun), fluorescence (noun), we record the temperature (clause). Three different shapes.

✅ Fixed: "Each tube undergoes three measurements: absorbance, fluorescence, and temperature."

One clean sentence replaces a padded, spliced, non-parallel one. The colon introduces the parallel list of three nouns; the expletive and the splice are gone. Word count fell by half, and precision rose.

Sentence 4 — agreement under "neither…nor" plus a splice

"Neither the calibration standards nor the blank was prepared fresh, this introduced a source of error."

Error 1 — agreement under correlative. With neither…nor, the verb agrees with the nearer subject. The nearer subject is the blank (singular), so was is… actually correct here. Lena got the tricky one right. (Had the order been "Neither the blank nor the calibration standards," it would need were.)

Error 2 — comma splice + orphan this. …prepared fresh, this introduced a source of error. Splice, and a bare this.

✅ Fixed: "Neither the calibration standards nor the blank was prepared fresh. This omission introduced a source of error."

The whole paragraph, repaired

"Following sample preparation, the centrifuge was run at 12,000 rpm for ten minutes. The supernatant, which contained the dissolved proteins needed for the assay, was then transferred to clean tubes. This step is critical, because contamination at this stage invalidates the results. Each tube undergoes three measurements: absorbance, fluorescence, and temperature. Neither the calibration standards nor the blank was prepared fresh. This omission introduced a source of error."

What changed, and what didn't

Not one experimental fact changed. Lena's science was correct from the first draft; the sentences were broken in ways that would have made a reviewer stumble — and a reviewer who stumbles is a reviewer who doubts. The repair was entirely mechanical: name the error family, apply the fix. Six sentences now, each correct, varied in length (9, 17, 9, 8, 9, 5 words), each pinning its meaning precisely.

The takeaway for your own methods sections: the reader judges your rigor partly by your sentences. A dangling modifier in a methods paragraph doesn't just look careless — it momentarily claims the centrifuge prepared the samples, and a careful reviewer notices. In writing meant to prove you were careful, careless sentences undercut the very thing you're trying to demonstrate. Run the five-pass error hunt (the Project Checkpoint) on every methods section before submission. It's the cheapest credibility you'll ever buy.