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Generative AI's failure to induce robust models of the world

garymarcus.substack.com

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Re: Generative AI's failure to induce robust models of the world

#21
This paper argues the opposite

https://arxiv.org/abs/2506.01622

Are world models a necessary ingredient for flexible, goal-directed behaviour, or is model-free learning sufficient? We provide a formal answer to this question, showing that any agent capable of generalizing to multi-step goal-directed tasks must have learned a predictive model of its environment. We show that this model can be extracted from the agent's policy, and that increasing the agents performance or the complexity of the goals it can achieve requires learning increasingly accurate world models. This has a number of consequences: from developing safe and general agents, to bounding agent capabilities in complex environments, and providing new algorithms for eliciting world models from agents.

Re: Generative AI's failure to induce robust models of the world

#22

The whole thing is silly. Look, we know that LLMs are just really good word predictors. Any argument that they are thinking is essentially predicated on marketing materials that embrace anthropomorphic metaphors to an extreme degree. Is it possible that reason could emerge as the byproduct of being really good at predicting words? Maybe, but this depends on the antecedent claim that much if not all of reason is stric…

I don't think it's accurate anymore to say LLMs are just really good word predictors. Especially in the last year, they are trained with reinforcement learning to solve specific problems. They are functions that predict next tokens, but the function they are trained to approximate doesn't have to be just plain internet text.

Yeah, that's fair. It's probably more accurate to call them sequence predictors or general data predictors than to limit it to words (unless we mean words in the broad, mathematical sense) they are free monoid emulators

Re: Generative AI's failure to induce robust models of the world

#23

The whole thing is silly. Look, we know that LLMs are just really good word predictors. Any argument that they are thinking is essentially predicated on marketing materials that embrace anthropomorphic metaphors to an extreme degree. Is it possible that reason could emerge as the byproduct of being really good at predicting words? Maybe, but this depends on the antecedent claim that much if not all of reason is stric…

> this depends on the antecedent claim that much if not all of reason is strictly representational and strictly linguistic. It's not obvious to me that this is the case I'm with you on this. Software engineers talk about being in the flow when they are at their most productive. For me, the telltale sign of being in the flow is that I'm no longer thinking in English, but I'm somehow navigating the problem / solution s…

Couldn't agree more. I look forward to the other side of this current craze where we actually have reasonable language around what these machines are best for.

On a more general level, I also never understood this urge to build machines that are "just like us". Like you I want machines that, arguably, are best characterized by the ways in which they are not like us—more reliable, more precise, serving a specific function. It's telling that critiques of the failures of LLMs are often met with "humans have the same problems"—why are humans the bar? We have plenty of humans. We don't need more humans. If we're investing so much time and energy, shouldn't the bar be bette than humans? And if it isn't, why isn't it? Oh, right it's because actually human error is good enough and the actual benefit of these tools is that they are humans that can work without break, don't have autonomy, and that you don't need to listen to or pay. The main beneficiaries of this path are capital owners who just want free labor. That's literally all this is. People who actually want to build stuff want precision machines that are tailored for the task at hand, not some grab bag of sort of works sometimes stochastic doohickeys.

Re: Generative AI's failure to induce robust models of the world

#24
post #18

Earlier quoted context omitted.

He cites o3 and o4-mini as examples of LLMs that play illegal chess moves.

I don't understand the reasoning behind drawing a conclusion that if something fails a task that requires reasoning implies that thing cannot reason. To use chess as an example. Humans sometimes play illegal moves. That does not mean Humans cannot reason. It is an instance of failing to show proof of reasoning. Not a proof of the inability to reason.

I don't think that's a fair representation of the argument.

The argument is not "here's one failure case, therefore they don't reason". The argument is that systematically if you given an LLM problem instances outside training sets in domains with clear structural rules, they will fail to solve them. The argument then goes that they must not have an actual model or understanding of the rules, as they seem to only be capable of solving problems in the training set. That is, they have failed to figure out how to solve novel problem instances of general problem structures using logical reasoning.

Their strict dependence on having seen the exact or extremely similar concrete instances suggests that they don't actually generalize—they just compute a probability based on known instances—which everyone knew already. The problem is we just have a lot of people claiming they are capable of more than this because they want to make a quick buck in an insane market.

Re: Generative AI's failure to induce robust models of the world

#25
post #18

Earlier quoted context omitted.

I don't understand the reasoning behind drawing a conclusion that if something fails a task that requires reasoning implies that thing cannot reason. To use chess as an example. Humans sometimes play illegal moves. That does not mean Humans cannot reason. It is an instance of failing to show proof of reasoning. Not a proof of the inability to reason.

I don't think that's a fair representation of the argument. The argument is not "here's one failure case, therefore they don't reason". The argument is that systematically if you given an LLM problem instances outside training sets in domains with clear structural rules , they will fail to solve them. The argument then goes that they must not have an actual model or understanding of the rules, as they seem to only be…

That still seems unfalsifiable. If it fails one instance the claim is that the failure is representative of things outside the training set. If it succeeds the claim is that it is in the training set. Without a definitive way to say something is not in the training set (a likely impossible task) the measure of success or failure is the only indicator of the purported reason reason for the success or failure.

Given models can get things wrong even when the training data contains the answer, failure cannot show absence.

Re: Generative AI's failure to induce robust models of the world

#26

This paper argues the opposite https://arxiv.org/abs/2506.01622 Are world models a necessary ingredient for flexible, goal-directed behaviour, or is model-free learning sufficient? We provide a formal answer to this question, showing that any agent capable of generalizing to multi-step goal-directed tasks must have learned a predictive model of its environment. We show that this model can be extracted from the agent'…

I only skimmed it so far, but this seems to only argue against the functional import of the OP, not its philosophical import.

On my reading, the philosophical claim is that these models do not develop an actual logical, internal representation of domains.

The functional import is whether or not they are able to realize specific behaviors within a domain. The paper argues that a markov process can realize the functional equivalence of the initial goal oriented picture of its domain—that is can solve goals with an error bound—but not that it develops an actual representation of the domain.

Lack of an actual representation prevents such a machine from doing other things. For example, iiuc, it would be unable to solve problems in domains that are homomorphic to the original, while an explicit representation does enable this.

Re: Generative AI's failure to induce robust models of the world

#28
post #25

Earlier quoted context omitted.

I don't think that's a fair representation of the argument. The argument is not "here's one failure case, therefore they don't reason". The argument is that systematically if you given an LLM problem instances outside training sets in domains with clear structural rules , they will fail to solve them. The argument then goes that they must not have an actual model or understanding of the rules, as they seem to only be…

That still seems unfalsifiable. If it fails one instance the claim is that the failure is representative of things outside the training set. If it succeeds the claim is that it is in the training set. Without a definitive way to say something is not in the training set (a likely impossible task) the measure of success or failure is the only indicator of the purported reason reason for the success or failure. Given mo…

I do think there are cases which, in controlled environments, there is some degree of knowledge as to what is in the training set. I also don't thin it's as impossible as you assume.

If you really wanted to ensure this with certainty just use the natural numbers to parameterize an aspect of a general problem. Assume there are N foo problems in the training set, then there is always a case N+1 parameter not in the training set, and you can use this as an indicative case. Go ahead and generate an insane number of these and eventually the probability that the Mth instance is not in the set is effectively 1.

Edit: Of course, it would not be perfect certainty, but it is probabilistically effectively certain. The number of problem instances in the set is necessarily finite, so if you go large enough you get what you need. Sure, you wouldn't be able to say there is a specific problem instance not in the set, but the aggregate results would evidence whether or no the LLm deals with all cases or (on assumption) just known ones.

Re: Generative AI's failure to induce robust models of the world

#29
post #18

Earlier quoted context omitted.

I don't understand the reasoning behind drawing a conclusion that if something fails a task that requires reasoning implies that thing cannot reason. To use chess as an example. Humans sometimes play illegal moves. That does not mean Humans cannot reason. It is an instance of failing to show proof of reasoning. Not a proof of the inability to reason.

I don't think that's a fair representation of the argument. The argument is not "here's one failure case, therefore they don't reason". The argument is that systematically if you given an LLM problem instances outside training sets in domains with clear structural rules , they will fail to solve them. The argument then goes that they must not have an actual model or understanding of the rules, as they seem to only be…

The lack of rigor and evidence behind the argument is the problem.

Re: Generative AI's failure to induce robust models of the world

#30

Earlier quoted context omitted.

I think the point is that category errors or misinterpreting what a tool does can be dangerous. Both statistical data generators and actual reasoning are useful in many circumstances, but there are also circumstances in which thinking that you are doing the latter when you are only doing the former can have severe consequences (example: building a bridge). If nothing else, his perspective is a counterbalance to what…

> If nothing else, his perspective is a counterbalance to what is clearly an extreme hype machine that is doing its utmost to force adoption through overpromising, false advertising, etc. These are bad things even if the tech does actually have some useful applications. In other words, overhyped in the short term, underhyped in the long term. Where short and long term are extremely volatile. Take programming as an ex…

The improvements in programming are largely due to the adoption of “agentic” architectures. This is really a hybrid neural-symbolic approach: the symbolic part being the interpreter/compiler. Effectively the LLM still produces an almost-correct-but-wrong program and then the compiler “fact-checks” it and then the LLM basically local-searches its way from there to something that passes the compiler. (If you want to be disabused of the idea that LLMs on their own are good at programming, just review the “reasoning” log of one trying to fix a simple string | undefined error in Typescript).

It seems clear to me therefore that further improvements in programming ability will not come from better LLM models (which have not really improved much), but from better integration of more advanced compilers. That is, the more types of errors that can be caught by the compiler, the better chance of the AI fuzzing its way to a good overall solution. Interestingly, I hear anecdotally that current LLMs are not great at writing Rust, which does have an advanced type system able to capture more types of errors. That’s where I’d focus if I was working on this. But we should be clear that the improvements are already largely coming via symbolic means, not better LLMs.

I wrote some notes about a year ago about the irony of LLMs being considered a refutation of GOFAI when they are actually now firmly recapitulating that paradigm: https://neilmadden.blog/2024/06/30/machine-learning-and-the-...

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