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eminence32 • yesterday at 8:22 PM • 8 replies • view on HN

I'm sort of surprised it took Jev for everyone to realize "oh yeah, this is a useful thing that we should have in our product portfolio".

But maybe this is one of those things that's only obvious in retrospect? I'm sure people were trying something similar years ago with grammar-constrained outputs (for example to only output a simple json structure), but you can't get probabilities out of the model that way. Which makes me wonder: how do these models calculate probabilities?


Replies

janalsncm • yesterday at 9:11 PM

A lot of AI stuff is like that, actually. GPT 2 and 3 were mainly curiosities that would get articles on tech news sites but didn’t attract much attention from the general public. But after RLHF the UX improved dramatically and ChatGPT became mainstream. A lot of MLEs underestimate how much UX matters, and the same is true for Jev.

> how do these models calculate probabilities?

The short answer is: more and better data.

The long answer is: probably the same way any other classifier does. Take your ground truth probabilities and your predicted probabilities. The gap between those is called cross entropy, which is used to push the model towards the correct probabilities.

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RomanKornev • yesterday at 11:26 PM

That's how the original Transformer architecture (LaMDA) should have been released back in the day, but Google thought it would cannibalize their search revenue.

JamesSwift • yesterday at 8:54 PM

I think its more like how LLMs caught everyone by surprise. A reasonable person would not think such a simple system would have been this effective, and yet here we are. Distilling that system down even further into a decision model again does not seem like it should work. But it seems to.

The whole system is foreign to us, and makes us rethink what "intelligence" actually is.

NitpickLawyer • yesterday at 8:46 PM

You can do it with LLMs by looking at the logprobs of ('yes', 'Yes', 'YES'...) vs. ('no'...). This works for bool or whatever they call it in jev space nool I think?

You can do it manually or use ready made libs. I know there's one in python on top of vllm that can do something like this.

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ashdksnndck • yesterday at 9:27 PM

We were doing zero and few-shot classification with LLMs since before they could reliably complete whole sentences. It’s an easier task than generating coherent text. The model needed to be tuned for classification (not generation) and for the domain, but it would often succeed at new classification tasks with a simple description.

I guess given the huge advances in LLM since then, these models probably achieve much better accuracy on a wide range of domains with lower effort compared to what we were doing, which makes it compelling as a product. And yeah, the models probably were already good enough a few years ago too. Other factors include how easy it is to release products at high speed now, and the desire in the industry to reduce token spend.

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jgalt212 • yesterday at 10:36 PM

> I'm sort of surprised it took Jev for everyone to realize "oh yeah, this is a useful thing that we should have in our product portfolio".

Because it's especially parsimonious with token use.

nrightnour • yesterday at 9:52 PM

OpenAI was already working on a Decisions API, and Jev launched theirs quickly enough to have 1 week in the spotlight before OpenAI put theirs in beta (which works great btw).

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