There was a famous-ish study about this a couple months ago that showed that llms training on llm generated data get dumber. I can't remember the name. I'm not

There was a famous-ish study about this a couple months ago that showed that llms training on llm generated data get dumber. I can't remember the name. I'm not sure if that result is holding up though, I've seen some ideas of generating 'textbook quality' data that might work