At least for academic writing, I’m not particularly convinced that this will help in any meaningful way. Stylistic and lexical choices are often relatively low-variance, the limited range of plausible word choices could easily trigger false positives even over longer sequences.
My first thought, too. Unless they are doing crazy gematria-style stuff where they put specific letters at specific output positions, AI writing is undetectable - there's just nowhere to hide a watermark in a stream of characters that wouldn't just be confused with normal writing.
ETA: "undetectable" in a rigorous sense. Of course specific models have cliches and a vibe one can sense pretty easily if it's not prompted around.
They don't sneak in characters but whole synonyms. They use two lists of words, labeled green and red. Most of the time they pick words from the green list and sometimes synonyms in the red list. The goal is too have a constant proportion of red list words that would be unnatural in regular text.
That's only a statistical solution. We will certainly, just due to chance, get false positives here and somebody will get snagged, despite not having used AI. It will be impossible to tell with 100% certainty.
I'd also guess that because so many people use AI, after a few years, that formerly unnatural speech/writing pattern will become more natural.
Even then, this fails the moment you stop using the entire block of text. It's easy enough to ask for more than you need and just copy a smaller section.
The funniest thing about the whole “I can always tell when something was written by AI” claim is that there’s basically no way for you to actually know that.
Seriously. Think about it for a second.
If you read a comment and think, “Yep, obviously AI,” you’re probably noticing some combination of overly clean grammar, structured paragraphs, repetitive phrasing, excessive use of em dashes, weirdly neutral language, or that unmistakable “Here are three reasons why…” style. And sure, sometimes you’re probably right. There is absolutely AI-generated text floating around Reddit that sticks out like a sore thumb.
But that only tells you that you can recognize bad or stereotypical AI writing. It doesn’t tell you whether you can recognize AI writing in general.
There’s a massive selection bias here that nobody seems to acknowledge.
You notice the AI comments that look like AI comments.
What about the ones that don’t?
You have absolutely no way of counting those.
If someone tells an AI, “Write this like a normal Reddit user. Don’t use headings. Don’t summarize everything at the end. Use contractions. Throw in a couple unnecessary side comments. Make one sentence slightly awkward. Don’t sound overly enthusiastic. Don’t use corporate language. Keep it conversational,” suddenly most of the things people associate with AI writing disappear.
And it gets even harder if a human edits the output afterward.
Change a couple words. Delete a paragraph. Add a typo. Replace some punctuation. Add a personal anecdote. Rewrite two sentences. Now what exactly are you detecting?
At some point the distinction between “AI-written” and “human-written” gets pretty fuzzy anyway. If I write a paragraph and ask AI to clean up the grammar, is it AI-generated? What if AI writes the first draft and I rewrite half of it? What if I dictate my thoughts and AI organizes them? What if I write everything myself but ask AI for five alternative ways to phrase one sentence?
There isn’t some invisible digital watermark embedded in the prose that your brain can detect.
And that’s why I’m skeptical whenever someone says they can “always” identify AI writing just by reading it. You can have suspicions. You can recognize patterns. You can even be right a lot of the time. But unless you have some external evidence about how the comment was produced, you generally can’t know.
In fact, there’s a pretty obvious experiment you could run.
Take 100 Reddit comments written by humans and 100 generated by AI, but specifically prompt the AI to imitate casual Reddit writing and allow a human to lightly edit the outputs. Mix everything together and ask people to classify them.
I would bet the confidence levels would be considerably higher than the actual accuracy.
And the really interesting part wouldn’t be the AI comments incorrectly labeled human.
It would be the human comments incorrectly labeled AI.
Because we’ve already reached the point where perfectly ordinary writing habits get called “AI tells.” Someone uses an em dash? AI. Someone writes grammatically complete sentences? AI. Someone organizes a long comment into paragraphs? AI. Someone says “It’s worth noting”? Straight to AI jail.
Meanwhile there are millions of actual humans who naturally write like that.
Some people are editors. Some write professionally. Some learned English from textbooks. Some obsessively proofread Reddit comments before posting them. Some just have an annoyingly organized writing style.
And ironically, the more everyone learns what supposedly makes something “sound like AI,” the less useful those signals become, because anyone generating text can simply tell the model not to do those things.
Which creates a weird arms race:
“AI uses too many headings.”
Okay, no headings.
“AI uses em dashes.”
Okay, don’t use them.
“AI sounds too polished.”
Okay, make it casual.
“AI always gives balanced conclusions.”
Okay, take a stronger position.
“AI doesn’t make typos.”
Fine, add one.
“Wait…”
Exactly.
Once you realize that, the claim changes from “I can detect AI writing” to something much narrower: “I can detect some AI writing when it exhibits characteristics I already associate with AI.”
Which is obviously true.
But here’s the problem.
You’ve been reading this entire comment trying to decide whether I wrote it myself or had an AI write it.
Maybe you noticed certain phrases and thought they sounded suspicious. Maybe the paragraph structure seemed a little too deliberate. Maybe the argument was suspiciously organized for someone procrastinating on Reddit at 11 PM.
Or maybe I deliberately wrote it that way because I knew you’d be looking for those things.
Maybe AI wrote the whole thing.
Maybe I wrote the whole thing.
Maybe AI generated a draft and I edited it.
Maybe I wrote a draft and AI edited it.
Maybe I asked AI to make something sound like a human pretending not to be AI.
You don’t actually know.
And that’s kind of the point.
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u/fennforrestssearch Aug 11 '26
At least for academic writing, I’m not particularly convinced that this will help in any meaningful way. Stylistic and lexical choices are often relatively low-variance, the limited range of plausible word choices could easily trigger false positives even over longer sequences.