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by gerdesj 558 days ago
"It" does not know when it does not know. A LLM is a funny old beast that basically outputs words one after another based on probabilities. There is no reasoning as we would know it involved.

However, I'll tentatively allow that you do get a sort of "emergent behaviour" from them. You do seem to get some form of intelligent output from a prompt but correctness is not built in, nor is any sort of reasoning.

The examples around here of how to trip up a LLM are cool. There's: "How many letter "m"s in the word minimum" howler which is probably optimised for by now and hence held up as a counterpoint by a fan. The one about boxes adding up to 1000 will leave a relative of mine for lost for ever but they can still walk and catch a ball, negotiate stairs and recall facts from 50 years ago with clarity.

Intelligence is a slippery concept to even define, let alone ask what an artificial one might look like. LLMs are a part of the puzzle and certainly not a solution.

You mention the word "edge" and I suppose you might be riffing on how neurons seem to work. LLMs don't have a sort of trigger threshold, they simply output the most likely answers based on their input.

If you keep your model tightly ie domain focussed and curate all of the input then you have more chance of avoiding "hallucinations" than if you don't. Trying to cover the entirety of everything is Quixotic nonsense.

Garbage in; garbage out.

1 comments

"It" does not know when it does not know.

But it does know when it has uncertainty.

In the chatgpt api this is logprobs, each generated token has a level of uncertainty, so:

"2+2="

The next token is with almost 100% certainty 4.

"Today I am feeling"

The next token will be very uncertain, it might be "happy", it might be "sad", it might be all sorts of things.

"The next token is with almost 100% certainty 4."

By using the word "almost" with regards 2 + 2 = 4, you have not exactly dispelled LLM "nonsense".

A human (with a modicum of maths knowledge) will know that 2 + 2 = 4 (pure integers - a fact by assertion). A maths worrier will get slightly uncomfortable about 2.0 + 2.0 = 4.0 unless they are ensured that decimal places and accuracy are the same thing and a few other things.

A LLM will almost certainly "know" something that is certain, if its training set is conclusive about that. However, it does not know why and if enough of the training set is suitably ambiguous then it (LLM) will drift off course and seem to spout bollocks - "hallucinate".

You might be in the wrong thread. This is merely a comment about whether LLMs hold a concept of uncertainty, they do.

Also, the next token might be 2 and the next token might be ², the next token could also have been x, these are all valid statements and the LLM might have been uncertain because of them.

2+2=4

2+2=x

2+2=2x

2+2=2x2

2+2=2²

Are all valid statements.

And somewhere in its training data, you can be sure there's also 2+2=5.
Yes, but most likely it's marked as false or incorrect through fine tuning or some form of reinforcement.

The idea that the logprobs of any token is proportional to the amount of times it comes up in training data is not true.

For example, suppose that A is a common misconception and is repeated often in Reddit, but B appears in scholarly textbooks and papers, and higher reputation data sources. Then through reinforcement the logprobs of B can increase, and they can increase consistently when surrounded by contexts like "This is true" and conversely decrease in contexts of "this is not true".

So the presumptions and values of its trainers are also embedded into the LLM in addition to those of the authors of the text corpus.