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by joshuahedlund 1085 days ago
> how does the "hallucination" issue differ from the same behaviour we see in humans?

In humans “hallucination” means observing false inputs. In GTP it means creating false outputs.

Completely different with massively different connotations.

3 comments

Great point, perhaps “confabulation” is a better way of describing it, which means “the replacement of a gap in a person's memory by a falsification that they believe to be true”. For example, the term is sometime used to describe dementia patients, who might wander somewhere and forget how they got there. The patient then might confabulate a story about why they are there, e.g. they were getting their keys so they could drive to the store to run an errand, despite the fact they no longer have a car.
That's kind of the point, but also kind of not.

GPT isn't making true or false outputs. It's just making outputs. The truthiness or falseness of any output is irrelevant because it has no concept of true or false. We're assigning those values to the outputs ourselves, but like... it doesn't know the difference.

It's like blaming a die for a high or a low roll - it's just doing rolls. It has no knowledge of a good or a bad roll. GPT is like a Rube Goldberg machine for rolling dice that's _more likely_ to roll the number that you want, but really it's just rolling dice.

> It's just making outputs.

Yeah, one way to conceive of the issue is that GPT doesn't know when to shut up. Intuitively, you can kind of understand how this might be the case: the training data reflects when someone did produce output, not when they didn't, which is going to bias strongly toward producing confident output.

A lot of the conversation about GPT hallucinations has felt like an extended rehash of the conversations we've been having out the difference between plausible and accurate machine translations since like, 2016ish.

You could apply the same logic to humans.

Whenever a human speaks, it's just vibrations of wave molecules, triggered by the mouth and throat, which in turn are controlled by electric signals in the human's neural network. Those neurons, they just make muscles move. They don't have any concept of true of false. At least nobody has found a "true of false" neuron in the brain.

all of it coheres to consciousness, we know what it's like to be a human, but I think it'd be hubris to think we've cracked the code and made a blueprint of anything other than a word calculator
Hubris goes both ways. It is also hubris to assume our intelligence is special, instead of a boring neural network with sufficient number of neurons that exhibit emergent properties.
There's probably more dimensions to hubris but typically I understand it as flying too close to the sun, the other way for me is humility.
It’s more than next-word prediction though. The supervised fine tuning and RLHF steps are ways to possibly train it to favor truthful answers. Not sure whether this is currently the emphasis of ChatGPT though…
> In humans “hallucination” means observing false inputs.

How do you know that? You can only observe the output of the humans (other than yourself).

A person can hallucinate under the effects of drugs or mental disorder and then tell you about it after they've recovered from it.

This experience is available to you and is well documented.

How do you know they are observing false inputs, as opposed to creating false outputs? (acting as if they have seen halucinations)

How do you know that the LLM is not observing false inputs but creating false outputs? Would an LLM which tells you very convincingly about how it obtained a false information make you change your mind?

> This experience is available to you and is well documented.

You are misunderstanding what I'm asking. Sure, drug induced hallucinations in humans is very well documented. What I'm asking if this purported difference between "hallucinating on the inputs" vs "creating false outputs" is meaningful distinction.