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This is certainly not agreed. Computer scientists here don't even have a theory of meaning, because it isn't part of the discipline, nor do almost any have any
by mjburgess 2y ago
This is certainly not agreed. Computer scientists here don't even have a theory of meaning, because it isn't part of the discipline, nor do almost any have any prior research background in it -- hence making these sort of outrageous claims all over the place. However you want to give natural language semantics, ML models certainly to not use this semantics.
The very best that might be said is that the correlational structure of words under transformer-like supervision (ie., where "predict the next word" is the goal) produces a distribution which is an extremely approximate model of natural language semantics.
Though this has never been disputed. The question comes down to what kind of extreme approximation is involved.
Eg., the truth conditions for "I have a pen in my hand" are that I have a pen in my hand -- direct access to these truth conditions is very plausibly necessary to mean "I have a pen in my hand" in the relevant context. Since a machine has no access to the truth conditions of such utterances it cannot possibly mean them.
Thus if a machine manages to say, "I have a pen in my hand" at an appropriate occasion -- the "extreme approximation to natural language semantics" has to do with this occasion and what "appropriateness" means.
Critics of LLMs and "computer-science-addled thinking" about such matters (such as myself) would say that there are a very narrow range of "occasions" (ie., situations in which you're prompting) that allow such responses to seem appropraite.
That a response seems appropriate to a user is a good engineering condition on a tool working -- it has nothing to do with whether a model understands natural language semantics.
What we might say is that it approximates conversations between agents who understand such semantics on a narrow range of occasions, and succeeds in modelling appropriate language use. And so you might call LLMs models of 'average appropriateness of replies'.
It obviously does not, nor cannot mean, "I have a pen in my hand"
- idiotsecant 2y agoIn what way do you have access to the truth conditions for 'I have a pen in my hand' that an LLM can not? This smells circular to me.
- deleted 2y ago[deleted]
- mjburgess 2y agoWell, by having a hand, and having a pen in it
- idiotsecant 2y agoI see. Your sense of sight is in some sense 'true' in a way that a webcam feed is not?
- mjburgess 2y agoWell if you can show me an LLM responding to it's having a pen in its hand via a robotic hand, webcam and the like -- then we are at the bare minimum for it possibly meaning, "i have a pen in my hand". No such LLMs exist, because they are trained to predict the next word not (WebCamState, RobotArmState, NextWord) -- since, at least, no such corpus exists
- magicalhippo 2y ago> No such LLMs exist, because they are trained to predict the next word not (WebCamState, RobotArmState, NextWord) Seems we might not be that far away given the work on action tokens[1] and such. NVIDIA divoted a lot of the CES presentation to this kind of stuff[2]. [1]: https://arxiv.org/abs/2403.19578 https://arxiv.org/abs/2403.19578 (semi-random example) [2]: https://www.nvidia.com/en-us/ai/cosmos/ https://www.nvidia.com/en-us/ai/cosmos/
- idiotsecant 2y agoIts pretty simple right now to present an llm with a text interface, a list of commands (turn head left turn head right, open hand, close hand, etc. And request they use those commands to achieve a goal. They can also almost all interpret images now. If I tell an llm that its objective is to look around until it finds its hand and tell me if its holding a pen or not, is that not exactly what you're talking about? Every single step there is well within the grasp of even the less advanced multimodal llms.
- 2y ago
- gjm11 2y agoThe truth conditions for the sentence "The composer Johann Sebastian Bach died in 1750" are not directly accessible to me. Can I mean that, if I say it? The truth conditions for "The god of the evangelical Christians exists" and "The god of the evangelical Christians does not exist" have, arguably, never been directly accessible to any ordinary human being. (Though some of their consequences could be accessible.) Can people mean such things, when they say them? The truth conditions for "There are infinitely many prime numbers" are ... unclear, really, but maybe they're vacuous (there is no possible world in which there aren't infinitely many prime numbers) or they involve only abstracta (such as those numbers). How do you feel about the possibility of an AI saying that and meaning it, and why? The first of these examples is the most directly relevant one. I have no direct access to the truth conditions of that sentence, but I think I can still mean it, have good reason to think it true, etc. The processes by which I got into that state involve ... learning things by reading about them, which is exactly what I think you're saying cannot in principle ever give genuine knowledge. Anticipating a possible response: Of course many of the other things I know, some of which are relevant to the way I understand those words, I learned more directly. For instance, part of what "died" means is the cessation of various natural processes like breathing and having one's heart beat, and I have direct experience of breathing and having a beating heart. One could argue that real knowledge and understanding needs to be somehow traceable back to direct experience, and therefore LLM-type systems cannot have them. But that would be a different argument from the one you've made, and I think it's less compelling (though more likely to be right!) than the simpler "knowledge isn't real unless it's based on direct access to the relevant truth conditions".
- mjburgess 2y agoThe mechanism of access varies depending on the claim made. "the sun is engaged in nuclear fusion" could not have been meant in 100 BC. But "I have a pen in my hand" could have. Julius Caeser could have made those sounds but he could never have meant the meaning of those words. ... to mean "I have" requires an "I" to "have", and so on. So what parts of non-linguistic reality language refers to matter for evaluating whether the user means what they say. An actor is likewise pretending to mean, and a child may say something without knowing what it means (as in, eg., a claim about nuclear fusion). If two children were immitating sounds to each other, such that one "said", "the sun is nuclear fusion" and so on -- then neither in this conversation are communicating, neither know what these words mean. No child involved could ever come up with these words in this worder, and mean their meaning, they can only have this conversation via immitation. This is the case with an LLM -- it's an imitation game wherein the game is to either fool the adult overheading the child, or to generate some userful material (depending whether you're the CEO or CTO). The problem with a "predict the next word" training goal is that any patterns which emerge will only be coincidentally related to the non-linguistic reality words refer to -- because the machine isn't trained on reference: it is not participating in reality and associating words with it. The kind of participation necessary for an agent to acquire the meaning of words has no universal answer, but it always "some". An LLM has none. For a claim about a composer, an agent who means to make this claim (rather than a child who imitates the sounds of words) -- must be aware of what a composer is, and so on. They cannot mean this claim if they don't have access to the non-linguistic reality to which these words refer (or are unable, via imgiation, to simulate similar ways the world might be, such that it has composers, given their prior knowledge -- eg., they at least have to have some prior direct access to music, leading-groups-of-people, and the like). We can slightly weaken all this but it'll make no difference for an LLM -- however weak we require access, to access the meaning of words requires accessing a non-lingusitic reality. Words mean non-ligustic things -- that is their point.