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How we measured AI writing across arXiv, and where the measurement breaks

unslop.run

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Re: How we measured AI writing across arXiv, and where the measurement breaks

#2
I scored the full text of 12,750 arXiv papers from 2021 through 2026 to find out how many of these get flagged as machine written and how much it increased since the release of chatGPT. I purposely tuned the detector to avoid false positives. My detection rate pre chatGPT is around .4% for that reason.

The biggest results: in Jan of 2026 about 39% of papers got flagged as AI written. In computer science speicifcally the peak was at 65%. Mathematics barely moved away from 0.7%, though the proof heavy math texts might just not get picked up by the detector properly.

All this is a detector estimate of a statistical signal and not a proof any given author used AI. Machine written can also mean heavy AI-assisted editing.

Re: How we measured AI writing across arXiv, and where the measurement breaks

#3
The important question is:

So what?

Genuinely. I get that there may be some visceral reaction against this, but when I break it down, I mostly fail to see the problem. Seems like what is actually important is:

Compared to before, when a human reads it, do they -- or society -- get something good out of it? Is it worth it to add this to the "pantheon?"

If that's not what's happening enough, and if this doesn't describe the process -- then the problem lies elsewhere, no?

Re: How we measured AI writing across arXiv, and where the measurement breaks

#4
post #3

The important question is: So what? Genuinely. I get that there may be some visceral reaction against this, but when I break it down, I mostly fail to see the problem. Seems like what is actually important is: Compared to before, when a human reads it, do they -- or society -- get something good out of it? Is it worth it to add this to the "pantheon?" If that's not what's happening enough, and if this doesn't describ…

The problem is that humans start with credulity. AI hallucinates and makes up stuff some percentage of the time. Humans are not "default deny" when given information. Unleashing that was a disservice to mankind and has created a future filled with lies and people who are confident in them.

Re: How we measured AI writing across arXiv, and where the measurement breaks

#5

I scored the full text of 12,750 arXiv papers from 2021 through 2026 to find out how many of these get flagged as machine written and how much it increased since the release of chatGPT. I purposely tuned the detector to avoid false positives. My detection rate pre chatGPT is around .4% for that reason. The biggest results: in Jan of 2026 about 39% of papers got flagged as AI written. In computer science speicifcally…

Thank you for this work.

Re: How we measured AI writing across arXiv, and where the measurement breaks

#6
post #3

The important question is: So what? Genuinely. I get that there may be some visceral reaction against this, but when I break it down, I mostly fail to see the problem. Seems like what is actually important is: Compared to before, when a human reads it, do they -- or society -- get something good out of it? Is it worth it to add this to the "pantheon?" If that's not what's happening enough, and if this doesn't describ…

Surprisingly I agree with you. My opinion is: if it makes communicating research more effective, while not reducing the quality of the output substantially, I see no issue.

A possible conclusion for this could be: If the majority of CS papers is AI written, let's just accept this reality universally and stop worrying about it altogether.

Re: How we measured AI writing across arXiv, and where the measurement breaks

#7

I scored the full text of 12,750 arXiv papers from 2021 through 2026 to find out how many of these get flagged as machine written and how much it increased since the release of chatGPT. I purposely tuned the detector to avoid false positives. My detection rate pre chatGPT is around .4% for that reason. The biggest results: in Jan of 2026 about 39% of papers got flagged as AI written. In computer science speicifcally…

This is a pretty stunning result. The time series looks really convincing. Is the way the detector itself is trained orthogonal to this or could there be some "leakage" in that the pre-chatgpt text is in the (positive) training data?

Re: How we measured AI writing across arXiv, and where the measurement breaks

#8
post #7

I scored the full text of 12,750 arXiv papers from 2021 through 2026 to find out how many of these get flagged as machine written and how much it increased since the release of chatGPT. I purposely tuned the detector to avoid false positives. My detection rate pre chatGPT is around .4% for that reason. The biggest results: in Jan of 2026 about 39% of papers got flagged as AI written. In computer science speicifcally…

This is a pretty stunning result. The time series looks really convincing. Is the way the detector itself is trained orthogonal to this or could there be some "leakage" in that the pre-chatgpt text is in the (positive) training data?

I tried my best to avoid leakage. If you're curious about how I trained the detector I have a writeup on it: https://unslop.run/blog/how-our-ai-text-detector-works

FYI this is all relatively new so there might be lots of issues and iterations coming.

Re: How we measured AI writing across arXiv, and where the measurement breaks

#9
post #3

The important question is: So what? Genuinely. I get that there may be some visceral reaction against this, but when I break it down, I mostly fail to see the problem. Seems like what is actually important is: Compared to before, when a human reads it, do they -- or society -- get something good out of it? Is it worth it to add this to the "pantheon?" If that's not what's happening enough, and if this doesn't describ…

Surprisingly I agree with you. My opinion is: if it makes communicating research more effective, while not reducing the quality of the output substantially, I see no issue. A possible conclusion for this could be: If the majority of CS papers is AI written, let's just accept this reality universally and stop worrying about it altogether.

> My opinion is: if it makes communicating research more effective, while not reducing the quality of the output substantially, I see no issue.

That's a big if. ArXiv is not peer reviewed and LLMs basically interpolate and extrapolate text, which makes them essentially fluff generators. Even in the most charitable interpretation, LLMs enable those with nothing to say to say nothing while meeting surface-level style guides.

Re: How we measured AI writing across arXiv, and where the measurement breaks

#10
post #3

The important question is: So what? Genuinely. I get that there may be some visceral reaction against this, but when I break it down, I mostly fail to see the problem. Seems like what is actually important is: Compared to before, when a human reads it, do they -- or society -- get something good out of it? Is it worth it to add this to the "pantheon?" If that's not what's happening enough, and if this doesn't describ…

Surprisingly I agree with you. My opinion is: if it makes communicating research more effective, while not reducing the quality of the output substantially, I see no issue. A possible conclusion for this could be: If the majority of CS papers is AI written, let's just accept this reality universally and stop worrying about it altogether.

I mean, sure. But what an absolutely insane predicate. "Not reducing the quality of the output substantially" is (as an AI might say...) load bearing there.

Other problems include: Signal to Noise Ratio going through the roof.

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