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Technical Report on the Pangram AI-Generated Text Classifier

Bradley Emi, Max Spero

2024 · arXiv

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From the abstract

We present Pangram Text, a transformer-based neural network trained to distinguish text written by large language models from text written by humans. Pangram Text outperforms zero-shot methods such as DetectGPT as well as leading commercial AI detection tools with over 38 times lower error rates on a comprehensive benchmark comprised of 10 text domains (student writing, creative writing, scientific writing, books, encyclopedias, news, email, scientific papers, short-form Q&A) and 8 open- and closed-source large language models. We propose a training algorithm, hard negative mining with synthetic mirrors, that enables our classifier to achieve orders of magnitude lower false positive rates on high-data domains such as reviews. Finally, we show that Pangram Text is not biased against nonnative English speakers and generalizes to domains and models unseen during training.

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Original HN comments, with labels from simple text rules. A label describes the whole comment and may miss context or irony. Read the discussion to make up your own mind. About the labels

7 selected excerpts · 7 total mentions

WhitneyLand
Neutral mention · rule
"Text is simply not information dense enough to be able to decode some arbitrary signal of provenance from it...it's a bad fiction to perpetuate that any of this is anything more than tarot card reading." Not true at all. Pangram is highly effective and has a very low false positive rate. The post here is impressive for a small project, it looks like they independently thought of one of the core ideas Pangram uses of creating twins to compare. You can see how it works here: https://arxiv.org/pdf/2402.14873
usefulposter
Neutral mention · rule
I'm not affiliated with it in any way, but you might want to check out the leading model https://arxiv.org/abs/2402.14873 and the mixed authorship detection https://www.pangram.com/blog/pangram-3-0-technical. LLM detection has come a long way since the first GPTZero. Human heuristics - I've prompted millions of tokens across every frontier model iteration for all manner of writing styles and purposes - also helps greatly. Concerning to me are long-time posters who (perhaps unknowingly) advance the decline of this human community by encouraging the people breaking HN guidelines. Perhaps spending a few hours on Moltbook might help develop such a heuristic, since "someone who knows how to write" is just a Claude model with a link to the blogpost. https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu... Thanks for your comment!
EdwardDiego
Neutral mention · rule
Human editors, I suspect, would pick up the "tells" of generated text, although as we know, there's a lot of false positives in that space. But it looks like Pangram is a text classifying NN is trained using a technique where they get a human to write a body of text on a subject, and then various LLMs to write a body of text on the same subject, which strikes me as a good way to approach the problem. Not that I'm in anyway qualified to properly understand ML. More details here: https://arxiv.org/pdf/2402.14873
gamegoblin
Neutral mention · rule
AI detectors in general are unreliable, but there are a few made by serious researchers that have only 1-in-10000 false positive rate, e.g. https://arxiv.org/pdf/2402.14873 Having worked in a bigcorp, I've read my fair share of management-speak, and none of it sounds quite as empty as the allegedly AI text. The AI sounds like someone conjuring a parody emulation of management speak instead of actual management speak. More broadly — and I feel this way about AI code at well as AI prose — I find that part of my brain is always trying to reverse engineer what kind of person wrote this, what was their mental state when writing it? And when reading AI code or AI prose, this…
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part of my brain short circuits a little. Because there is no cohesive human mind behind the text. It's kind of like how you subconsciously learn to detect emotion in tiny facial movements, you also subconsciously learn to reverse engineer someone's mind state from their writing. Reading AI writing feels like watching an alien in skinsuit try to emulate human face emotional cues — it's just not quite right in a hard-to-describe-but-easy-to-detect way.
agucova
Neutral mention · rule
I ran the introduction chapter through Pangram [1], which is one of the most reliable AI-generated text classifiers out there [2] (with a benchmarked accuracy of 99.85% over long-form text), and it gives high confidence for it having been AI-generated. It's also very intuitively obvious if you play a lot with LLMs. I have no problem at all reading AI-generated content if it's good, but I don't appreciate dishonesty. [1]: https://www.pangram.com/ [2]: https://arxiv.org/pdf/2402.14873
maxspero
Neutral mention · rule
We benchmark on pre-2023 datasets of O(10M) documents not in our training set. Other detectors seem to have between 1-3% false positive rate and ours is around 1 in 10,000 as of our latest model update. We do a lot of active learning + core set selection to keep FPR low and improve recall on larger LLMs. Our white paper with some methodology is here: https://arxiv.org/abs/2402.14873

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