Blog · 2026-10-15 · baryreview editors
How to write a correction prompt that actually fixes an article
You have an AI-drafted article, you can see it has problems, and you want the model that wrote it to fix them. The natural move is to paste it back with “improve this.” The result is a second draft with different problems and the same word count. A prompt to fix AI writing has to work like an editor’s markup: it names the passage, says what is wrong, and says what to do instead, with rules about what not to touch.
This is the format our editors use when they write corrections for customers, and it works just as well when you write them yourself. Below: the method, a full worked example, and the mistakes that make correction prompts fail.
Why “make it better” fails
A model rewriting on a vague instruction has no way to know which parts you liked. It re-rolls the whole thing. Sentences that were fine become different sentences. A fact you had checked gets paraphrased into one you have not. The invented statistic in paragraph three survives, because nothing told the model it was invented, and the model does not know.
A correction prompt is specific in both directions: about what is wrong, and about what must stay the same. The model is good at applying a precise instruction to a located passage. It is bad at guessing what you meant by “better.”
The method, item by item
Constraints go first. Before any correction, state the rules: keep the author’s voice, add no new facts, statistics, quotes or examples, and change nothing you did not flag. Rules at the top apply to every item below. Without them, “fix the vague sentence” is an invitation to invent a specific one.
Number every item. Numbers make the output checkable, and let you say “redo item 4” instead of describing it again.
Each item is an instruction plus a quoted location. Quote the exact words, enough to be unique in the article. “The paragraph about pricing” is ambiguous; a quoted sentence is not. The model finds the quote, applies the instruction there, and leaves the surrounding text alone.
One problem per item. A sentence with a made-up statistic and a hedge is two items. Combined instructions get partially applied, and you cannot tell which half was missed.
Say what is wrong and what to do. Not “fix this.” The diagnosis tells the model what not to reintroduce; the action tells it what to produce. “This statistic cannot be verified. Delete the number and the attribution; state the point without a figure” gives it both.
Verify afterward. The revision is a new draft. Read it against the list, then once more as a reader.
A full worked example
Northwind Plumbing is a fictional company. A model drafted a blog post on tankless water heaters. Here is one paragraph, roughly 200 words, as it came out of the tool.
It’s no secret that tankless water heaters have become a popular choice for homeowners looking to save money, save space and save the planet. According to a 2023 study by the American Plumbing Institute, households that switch to tankless save an average of 47% on their energy bills, which makes the decision a no-brainer. Tankless units heat water on demand, so you’ll never run out of hot water, no matter how many showers are running at once. It’s important to note that installation can be somewhat more complex than a traditional tank, and some homes may require electrical or gas line upgrades, so it may be worth consulting a professional. At Northwind Plumbing, we guarantee our tankless installations will cut your utility bill in half, or your money back. Our certified technicians have installed thousands of units across the region. Tankless heaters typically last 20 years, compared to 10 to 15 for a tank, and they take up a fraction of the space. Whether you’re building a new home, replacing an old unit, or simply looking to upgrade, a tankless water heater is a smart, efficient and forward-thinking investment that will pay for itself in no time.
An informed reader finds six problems. The correction prompt:
You are revising one paragraph of a blog post for Northwind Plumbing.
Rules for this job:
- Keep the author's voice: plain, friendly, second person.
- Do not add any new facts, statistics, studies, quotes, names or
examples. If an instruction removes a claim, do not replace it with
a different claim.
- Change only the passages quoted below. Leave every other sentence
exactly as it is.
- Return the full revised paragraph, then a numbered list confirming
what you changed for each item.
Corrections:
1. "According to a 2023 study by the American Plumbing Institute,
households that switch to tankless save an average of 47% on their
energy bills" — We cannot find this organization or this study, and
the figure cannot be verified. Delete the sentence entirely,
including "which makes the decision a no-brainer." Do not substitute
another number or source.
2. "so you'll never run out of hot water, no matter how many showers
are running at once" — This is false. A tankless unit has a maximum
flow rate, and several simultaneous showers can exceed it. Replace
with a sentence that says a tankless unit supplies continuous hot
water up to its rated flow rate, and that running several fixtures
at once can exceed that rate.
3. "we guarantee our tankless installations will cut your utility bill
in half, or your money back" — Northwind does not offer this
guarantee and the result depends on the home. Remove the guarantee.
Replace with a plain statement that savings vary with household
size, usage and the unit being replaced.
4. "Our certified technicians have installed thousands of units across
the region" — Unverified claim about the company. Delete "thousands
of units across the region" and keep the sentence to what we can
stand behind: that our technicians are licensed and install tankless
units regularly.
5. "It's no secret that tankless water heaters have become a popular
choice for homeowners looking to save money, save space and save
the planet" — Empty opener and a tidy triad. Replace with one direct
sentence that says what the paragraph is about: whether a tankless
heater is the right choice for the reader's home.
6. "a smart, efficient and forward-thinking investment that will pay
for itself in no time" — Vague and makes a payback promise. Replace
"that will pay for itself in no time" with nothing, and reduce the
three adjectives to one plain statement that it is worth considering
for many homes but not all.
The paragraph after the model applied the prompt:
Is a tankless water heater the right choice for your home? Tankless units heat water on demand and supply continuous hot water up to their rated flow rate; running several showers and a dishwasher at once can exceed that rate, so the unit has to be sized for your household. It’s important to note that installation can be somewhat more complex than a traditional tank, and some homes may require electrical or gas line upgrades, so it may be worth consulting a professional. At Northwind Plumbing, we’ll tell you honestly what to expect: savings vary with household size, how much hot water you use, and the unit you’re replacing. Our technicians are licensed and install tankless units regularly. Tankless heaters typically last 20 years, compared to 10 to 15 for a tank, and they take up a fraction of the space. Whether you’re building a new home, replacing an old unit, or simply looking to upgrade, a tankless water heater is worth considering for many homes, though not every one.
Six items, six changes, nothing invented. The unflagged sentences are untouched, which is the point of the “change only the quoted passages” rule. The “It’s important to note” sentence survived because it was not on the list; that is correct behavior, and it becomes item 7 next pass, along with checking the 20-year lifespan figure against a manufacturer’s documentation. A correction prompt makes the changes you asked for and only those, so you always know what moved.
Common mistakes in a prompt to fix AI writing
Vague prompts. “Tighten this up,” “make it more engaging,” “sound less like AI.” Each is a request for a different draft, and you will have to re-read the whole piece to find out what changed. If you cannot quote the passage and name the problem, you have not finished diagnosing it.
“Make it better.” The worst version of vague. The model’s default idea of better is longer, smoother and more hedged, which is usually the opposite of what the article needs.
Letting the model add claims. This is the one that causes real damage. “This paragraph needs a statistic” will get you a statistic, with a year, a percentage and an organization, and a fair chance none of them exist. “Add no new facts” has to be explicit at the top and repeated inside any item that removes a claim. If the paragraph genuinely needs a number, you find it, verify it, and put it in the instruction yourself: “Replace with: ‘The Department of Energy estimates…’ and link to [URL].”
Fixing the symptom, not the cause. “Remove ‘no-brainer’” leaves the invented statistic it was attached to. Usually the tone problem is riding on a substance problem.
Combined items and missing locations. “Fix the stat, the hedge and the guarantee in paragraph two” will get two of three applied, and you will not know which. “The part about installation is too long” sends the model hunting. Quote the words.
No change list. Ask for the revised text and a numbered confirmation of what changed. The confirmation is where you catch “I also improved the flow of the surrounding sentences,” meaning it changed things you did not flag.
How to re-check the output
Three passes, in order.
- The list pass. For each numbered item, find the location and confirm the instruction was applied as written, not approximately. Item 2 asked for a flow-rate sentence; did it add a flow-rate figure you did not supply? That is a new claim and it goes.
- The diff pass. Compare the unflagged sentences to the original. Any change outside the quoted passages violates the constraints. Some models paraphrase lightly even when told not to; if yours does, say so next time (“You changed the sentence beginning ‘Tankless heaters typically last’; restore the original wording”).
- The reader pass. Read it once as a customer would, ignoring the list. Corrections leave seams: a sentence that refers to a figure you deleted, a “however” with nothing to contrast, two sentences that now say the same thing. These become the next round’s items.
Two rounds is normal for a paragraph with this many problems; three is not unusual for a full article. Each round is short because each prompt is specific.
Where this format comes from
This is the format of the email a baryreview customer receives: a cover note, then numbered corrections, each quoting the passage and saying what is wrong and what to do, with constraints at the top. You paste the block into the AI that wrote the article and it applies the fixes; there is a full one on the sample review page. We write corrections instead of rewriting for the same reason the format works: the article stays in your voice and your tool, and every change is one you can point to.
Takeaway
A correction prompt is an editor’s markup written for a model: constraints first, then numbered items that each quote one passage, name one problem and give one instruction. Never let the model fill a gap with a fact you did not supply, and always ask it to list what it changed. Then read the revision against the list, against the original, and once as a reader.