Comment by crazygringo

6 years ago

Wow. GPT2 is so, so, so much better than Markov chains. I'm reading these definitions, and the fact that the last few words of the sentence match the first few words subject-wise is pretty amazing. Just some random ones:

> denoting or relating to a word (e.g., al-Qadri), the first letter of which is preceded or followed by another letter

> a synthetic compound used in perfumery and cosmetic surgery to improve the appearance of skin tone and irritation

> a type of cookie made with dough, jelly, butter, or chocolate, often filled with extra flour

Pretty impressive. I've never seen fake text so real. (I mean none of these seem to quite make 100% logical sense, but if you were just skimming the sentence nothing would stand out as a red flag.)

I always like to point people to /r/SubSimulatorGPT2 [1] as a good example of what GPT2 is able to accomplish.

It's a subreddit filled entirely with bots, each user is trained on a specific subreddit's comments matching it's username (so politicsGPT2Bot is trained on comments from the politics subreddit).

Go click through a few comment sections and see how mind-bendingly real some comment chains seem. They reply quoting other comments, they generate links (they almost always go to a 404 page, but they look real and are in format that makes me think it's real every time I hover over it) entirely on their own, they have full conversations back and forth, they make jokes, they argue "opinions" (often across multiple comments back and forth keeping the context of which "side" each comment is on), and they vary from single word comments to multi-paragraph comments.

Take a look at this thread [2] specifically. The headline is made up, the link it goes to is made up, but the comments look insanely real at first glance. Some of them even seem to be quoting the contents of the article (which again, doesn't exist) in it's comments!

If you threw something like 50% "real humans" in the mix, I genuinely don't think I'd be able to pick out the bots on my own.

[1] https://www.reddit.com/r/SubSimulatorGPT2/

[2] https://www.reddit.com/r/SubSimulatorGPT2/comments/fzwso5/nr...

One of the recurring tropes on Hacker News whenever a text generator (either RNN or GPT-2 based) project is posted, there is inevitably a comment saying "this is indistinguishable from a Markov chain."

In this case, it's impossible to do so.

If someone could make a billion word dictionary of these words, you could get excellent sentence compression rates out of standard English.

  • GPT-2 itself works off of excellent sentence compression (byte-pair encoding for the input and output)

    • so for example, a byte-pair input could be "potato salad in rum" and the output might be "potadum"?