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Ask HN: When LLMs make stuff up, call it 'confabulating', not 'hallucinating'

36 points by irdc ↗ HN
In humans, a hallucination is formally defined as being a sensory experience without an external stimulus. LLMs have no sensors to experience the world with (other than their text input) and (probably) don’t even have a subjective experience in the same way humans do.

A more suitable term would be confabulation, which is what humans do when due to a memory error (eg. due to Korsakoff syndrome) we produce distorted memories of oneself. This may sometimes sound very believable to outsiders; the comparison with LLMs making stuff up is rather apt!

So please call it confabulating instead of hallucinating when LLMs make stuff up.

69 comments

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mejutoco
All seem valid to me. The inputs to training are the "sensor" through which LLM "experience the world". Maybe interpolation or extrapolation would be acceptable too.
andyjohnson0
I agree that confabulate is more accurate and descriptive. But in general usage "halucinate" is a commonly understood word and "confabulate " is not. Using the latter runs the risk of sounding off-puttingly technical or obscure.
baq
Good opportunity to change that!
gwd
This is exactly the problem: I'd heard the word "confabulate" before, but has a weird 19th-century feel to it, and didn't know that it was specifically about memory reproduction errors.

I think that humans actually confabulate in minor ways a lot more than we realize; just ask your parents to compare stories with their siblings about something that happened to them growing up -- in my experience you often get completely different versions of events. Given that, it might actually be a good opportunity (as the comment sibling suggests) to introduce that into the language.

mrob
The standard meaning of "confabulate" is just "chat". The "memory reproduction error" is psychology jargon. For this reason, I support continued use of "hallucinate" for LLM errors.
gwd
Right; so could we compare trying to get people to stop saying "hallucinate" to trying to get people to stop saying "tidal wave"?

(My understanding is that people the use the word "tidal wave" to mean the wave around the earth caused by the moon's gravity, which causes the tides; obvs this is quite different than a large wave caused by an earthquake.)

Kye
My mind immediately goes to the episode of Star Trek: TNG with Mark Twain when I hear confabulate.
chriskanan
This is what I've been calling it as well. Confabulation is much more appropriate as a term.
jamifsud
On a related note, are there promising models / techniques to detect these sort of instances?

Say for instance I summarize something and want to check that the result doesn't contain hallucinations (confabulations :)) or more specifically that the summary contains only information present in original text. What's current state of the art for something like this and how well does it perform? I've read some about entailment models and fine tuned LLMs for this sort of thing but haven't found many great resources.

BaculumMeumEst
Similar suggestions have been made over and over, and they've never stuck. "Hallucinating" has already hit mainstream media. It's probably going to stay that way out of sheer inertia because nobody outside of a small group of nerds on hackernews is going to sit down and think about whether "hallucinating" or "confabulating" more accurately describes the nature of the error. The existing term already captures the general idea well enough.
faichai
Hard disagree. I’m browsing the internet not surfing the Information Super Highway. Mainstream media needs to rely less on allegory once technology becomes mainstream.
krapp
LLMs aren't mainstream yet. When they are, it will simply be common cultural knowledge that they can (lie,hallucinate,confabulate,whatever) and metaphors won't be necessary, the way the internet became mainstream once it was common knowledge not to "feed trolls" or "click on spam."

At the moment, most people still think LLMs are basically like the computers from Star Trek, rational, sentient and always correct. Like those lawyers who used ChatGPT to generate legal arguments - it didn't even occur to them that AI could fabricate data, they assumed it was just a search engine you could talk to like a person.

This is why we still need metaphors to spread cultural knowledge. To that end I think it's less important to be technically accurate than to impart an idea clearly. "Hallucinate" and "confabulate" get the same point across, but the former is more widely understood.

Even "confabulate" isn't great, since it carries the connotation of either deception or senility/mental illness. But the "confabulation" of LLMs is inherent to their design. They aren't intended to discern truth, or accuracy, but statistical similarity to a stream of language tokens.

And humans don't really do that, so we don't really have language fit to describe how LLMs operate without resorting to anthropomorphism and metaphors from human behavior.

dtech
But hallucinating is not an allegory... Just like we're still using browsing.
chriswarbo
> I’m browsing the internet not surfing the Information Super Highway.

Hard disagree. You're browsing the Web not exploring the Internet.

m0rissette
And here I thought us nerds ruled the world.
quantified
The millenium parties were all on New Year's Eve of 2000, not New Year's Eve of 2001. Some nerds had to be worrying about Y2K date/time bugs instead of partying too.
karmakaze
The true nerds would be partying the next year with the millinium ending/beggining on Jan 1, 2001.
Am4TIfIsER0ppos
What exact date do you think "New Year's Eve of 2000" is? 2000-12-31?
quantified
It was the eve of the new year, the evening that started at the end of 1999-12-31 and ended in time for brunch on 2000-01-01. I was partying with the fun people after arguing the numbers for a few days in 1998 or 1999.
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unklefolk
When educating the general public about the risks and limitation of LLMs, I think "hallucinating" is a useful term - it is something people can understand and it conveys the idea of LLMs being somewhat random and unreliable in their responses. I'm not sure "confabulating" is so easily understood or accessible.
snordgren
Hallucinating also gets the point across that the LLM will sometimes be 100% sensible and 100% confident in its claims, while being 100% wrong in those claims.
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phowat
Why change something that is already a well defined term in the context of generative AIs ?
baq
Because it isn't really as well defined as you believe, but it has been well defined in context of neuropsychology?
phowat
I just searched for "ai hallucination" on arxiv and got 43 hits. And terms get reused in new contexts all the time. I don't disagree confabulating would be a more correct term, though.
irdc
This exactly: psychology and psychiatry have fully-developed lexicons for describing various phenomena which AI researchers would do well to adapt.
cr3ative
I don't see this as a more suitable term; I had to check the definition of "confabulate" and the first hit in the macOS dictionary is "formal; engage in conversation" and the second is "psychiatry; fabricate imaginary experiences".

The fact I had to look it up to make sure, and that it isn't the primary definition, makes this a bad alternative to a well understood word which has already become established.

dean2432
thank you for the description. as a non-native english speaker i haven't heard the word 'confabulate' before, while hallucinate i learned from a young age.
SturgeonsLaw
A huge portion of the English speaking world would also not know the meaning of confabulate
bregma
Given that the "I" in "AI" is already a strong misnomer, why not just go with the lies people get told and make a fast buck?
lopatin
It’s too late. People already call it hallucination and confabulating sounds weird. The idea that you think you can reverse the trend with a HN post is interesting though.
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baq
Language changes all the time, nothing is set in stone, and HN is one of the better places where this change can start happening. Media copycats will follow.
danielbln
The question is, why? Yeah, confabulation might capture the phenomeon better, but no-one knows the word, it is not commonly used, compared to hallucination. And that is across languages:

    Russian:
        Hallucination: Галлюцинация (Gallyutsinatsiya)
        Confabulation: Конфабуляция (Konfabulyatsiya)

    German:
        Hallucination: Halluzination
        Confabulation: Konfabulation

    French:
        Hallucination: Hallucination
        Confabulation: Confabulation

    Spanish:
        Hallucination: Alucinación
        Confabulation: Confabulación

    Italian:
        Hallucination: Allucinazione
        Confabulation: Confabulazione

    Portuguese:
        Hallucination: Alucinação
        Confabulation: Confabulação
If hallucination isn't a perfect fit, but everyone and their dog know roughly what it indicates in relation to LLMs then that's still better than forcing a word no-one ever uses to describe something slightly different but overall rather similar.
glandium
French also has affabulation, which means roughly the same thing (confabulation is actually defined as "affabulation in some severe pathological cases"), and is, AFAIK, commonly known.
alpaca128
> Language changes all the time

...towards less complexity and redundancy. Scientifically accurate terms are called that because they're usually not part of everyday language. Hallucination is a much more common word and thus more self-explanatory to most people. For a random person AI confabulation sounds about as intuitive as flux capacitor.

madeofpalk
The problem with describing factual errors as "hallucinating" is that they're no more or less hallucinations than when it generate correct content. The entire point of these LLMs is that it synthesises content not in the original input. It's always "hallucinating" - its just that sometimes it gets it right and sometimes it gets it wrong.
tsmarsh
I find the easiest way of explaining LLMs to laypeople is "Bulls*t Engine". If tuned well they're going to answer like a salesperson or internet troll: if they don't know they will BS before they don't answer. Its not hallucinating, or confabulation its BS.

That's not to say they're not useful. The ability to BS is well regarded among humans as long as you, as a consumer, have a decent BS detector. And like a good BS artist, if you stay within their area of expertise they can be really useful. Its when you ask them something that they should or almost know that they start to be full of s**.

jfengel
To me, "confabulating" implies deliberately attempting to mislead. I like "bullshit" better -- bullshitting might be lying, but it can also mean simply trying your best in the attempt to please. To the degree that an LLM "wants" something, it's to give you an answer that makes you happy, even if it doesn't know the truth.

The fact that BS is also used for deliberate lying to mislead is a strike against that word. Using "bullshit" and "hallucinate" in conjunction somewhat paint a picture of the quality of the answer you get and the "motivation" used to get there.

thaumasiotes
> A more suitable term would be confabulation, which is what humans do when due to a memory error (eg. due to Korsakoff syndrome) we produce distorted memories of oneself. This may sometimes sound very believable to outsiders; the comparison with LLMs making stuff up is rather apt!

Why? LLMs don't have memories any more than they have sensors.

irdc
The term describes externally-observable behaviour rather than falsely positing the existence of LLM internal mind-states.
thaumasiotes
That is a contradiction of the definition that you supplied.

Maybe decide what you think the words mean before you decide how other people will use them?

chromatin
While I agree with you that it's a better fit semantically, it won't happen, but not for the reasons given in the thread. The real reason is not the ignorance of the general public, but -- IMO -- the fact that even highly intelligent AI/ML engineers themselves have a limited vocabulary* and generally do not know this word.

* this is the prevailing secular trend, at least in the US

Kye
I had literally never heard this word before people started complaining about LLMs hallucinating. I think I'll stick with the one that makes sense and wait for dictionaries to catch up. Words literally can mean multiple things.
Ilnsk
Go back to Lesswrong.
rsynnott
Neither really seem appropriate; they're both far too anthropomorphising. The machine isn't making an error of _thought_; it's simply accidentally incorrect instead of accidentally correct.
gvx
In terms of communicating with laypeople, I don't think this is a hill worth dying on. "Confabulating" is not a term I think that many people outside of the field of psychology are familiar with in the first place.

If you do want to use another term for laypeople, I think "bullshitting" or "BSing" would have connotations that are more relevant than "hallucinating".

chalsprhebaodu
Confabulate is definitely a more suitable and sensible term for this. It’s clearly semantically more descriptive and would do a better job communicating what is actually happening.

The thing is, “confabulating” will never stick. People like myself will enter discussions about it and insist that it won’t stick, and because of that, I certainly won’t start using that term and hopefully I’ll convince a few others not to either.