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Comment by tinco

15 hours ago

Yeah I think LeCun is underestimating the impact that LLM's and Diffusion models are going to have, even considering the huge impact they're already having. That's no problem as I'm sure whatever LeCun is working on is going to be amazing as well, but an enterprise like Facebook can't have their top researcher work on risky things when there's surefire paths to success still available.

I politely disagree - it is exactly an industry researcher's purpose to do the risky things that may not work, simply because the rest of the corporation cannot take such risks but must walk on more well-trodden paths.

Corporate R&D teams are there to absorb risk, innovate, disrupt, create new fields, not for doing small incremental improvements. "If we know it works, it's not research." (Albert Einstein)

I also agree with LeCun that LLMs in their current form - are a dead end. Note that this does not mean that I think we have already exploited LLMs to the limit, we are still at the beginning. We also need to create an ecosystem in which they can operate well: for instance, to combine LLMs with Web agents better we need a scalable "C2B2C" (customer delegated to business to business) micropayment infrastructure, because as these systems have already begun talking to each other, in the longer run nobody would offer their APIs for free.

I work on spatial/geographic models, inter alia, which by coincident is one of the direction mentioned in the LeCun article. I do not know what his reasoning is, but mine was/is: LMs are language models, and should (only) be used as such. We need other models - in particular a knowledge model (KM/KB) to cleanly separate knowledge from text generation - it looks to me right now that only that will solve hallucination.

  • Knowledge models, like ontologies, always seem suspect to me; like they promise a schema for crisp binary facts, when the world is full of probabilistic and fuzzy information loosely categorized by fallible humans based on an ever slowly shifting social consensus.

    Everything from the sorites paradox to leaky abstractions; everything real defies precise definition when you look closely at it, and when you try to abstract over it, to chunk up, the details have an annoying way of making themselves visible again.

    You can get purity in mathematical models, and in information systems, but those imperfectly model the world and continually need to be updated, refactored, and rewritten as they decay and diverge from reality.

    These things are best used as tools by something similar to LLMs, models to be used, built and discarded as needed, but never a ground source of truth.

    • >Knowledge models, like ontologies, always seem suspect to me; like they promise a schema for crisp binary facts, when the world is full of probabilistic and fuzzy information loosely categorized by fallible humans based on an ever slowly shifting social consensus.

      I don't disagree that the world is full of fuzziness. But the problem I have with this portrayal is that formal models are often normative rather than analytical. They create reality rather than being an interpretation or abstraction of reality.

      People may well have a fuzzy idea of how their credit card works, but how it really works is formally defined by financial institutions. And this is not just true for software products. It's also largely true for manufactured products. Our world is very much shaped by artifacts and man-made rules.

      Our probabilistic, fuzzy concepts are often simply a misconception. That doesn't mean it's not important of course. It is important for an AI to understand how people talk about things even if their idea of how these things work is flawed.

      And then there is the sort of semi-formal language used in legal or scientific contexts that often has to be translated into formal models before it can become effective. Law makers almost never write algorithms (when they do, they are often buggy). But tax authorities and accounting software vendors do have to formally model the language in the law and then potentially change those formal definitions after court decisions.

      My point is that the way in which the modeled, formal world interacts with probabilistic, fuzzy language and human actions is complex. In my opinion we will always need both. AIs ultimately need to understand both and be able to combine them just like (competent) humans do. AI "tool use" is a stop-gap. It's not a sufficient level of understanding.

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    • World models are trivial. eg narratives are world models and they provide only pre frontal simulation, ie they are synthetically prey-predation. No animal uses world models for survival and doubtful they exist (maps are not models), a world model doesn't conform to optic flow, ie instantaneous use and response. Anything like a world model isn't shallow, the basic premise of oscillatory command, it's needlessly deep, nothing like brains. This is just a frontier hail-mary to the current age.

    • Is it that fuzzy though? If it was would language not adequately grasp and model our realities? And what about the physical world itself: animals are modeling the world adequately enough to navigate it. There's significant gains to make from modeling _enough_ of the world, without falling into hallucinations of purely statistical associations of an LLM.

    • You're basically describing the knowledge problem vs model structure, how to even begin to design a system which self-updates/dynamically-learns vs being trained and deployed.

      Cracking that is a huge step, pure multi-modal trained models will probably give us a hint, but I think we're some ways from seeing a pure multi-modal open model which can be pulled apart/modified. Even then they're still train and deploy not dynamically learning. I worry we're just going to see LSTM design bolted onto deep LLM because we don't know where else to go and it will be fragile and take eons to train.

      And less said about the crap of "but inference is doing some kind of minimization within the context window" the better, it's vacuous and not where great minds should be looking for a step forwards.

    • I have vague notions of there being an entire hidden philosophical/political battlefield (massacre?) behind the whole "are knowledge models/ontologies a realistic goal" debate.

      Starting with the sophomoric questions of the optimist who mistakes the possible for the viable: how definite of a thing is "the world", how knowable is it, what is even knowledge... and then back through the more pragmatic: by whom is it knowable, to what degree, and by what means. The mystics: is "the world" the same thing as "the sum of information about the world"? The spooks: how does one study those fields of information which are already agentic and actively resist being studied by changing themselves, such as easily emerge anywhere more than n(D) people gather?

      Plenty of food for thought from why ontologies are/aren't a thing. The classical example of how this plays out in the market being search engines winning over internet directories. But that's one turn of the wheel. Look at what search engines grew into quarter century later. What their outgrowths are doing to people's attitude towards knowledge. Different timescale, different picture.

      Fundamentally, I don't think human language has sufficient resolution to model large spans of reality within the limited human attention span. The physical limits of human language as information processing device have been hit at some point in the XX century. Probably that 1970s divergence between productivity and wages.

      So while LLMs are "computers speak language now" and it's amazing if sad that they cracked it by more data and not by more model, what's more amazing is how many people are continually ready to mistake language for thought. Are they all P-zombies or just obedience-conditioned into emulating ones?!?!?

      Practically, what we lack is not the right architecture for "big knowing machine", but better tools for ad-hoc conceptual modeling of local situations. And, just like poetry that rhymes, this is exactly what nobody has a smidgen of interest to serve to consumers, thus someone will just build it in their basement in the hope of turning the tables on everyone. Probably with the help of LLMs as search engines and code generators. Yall better hurry. They're almost done.

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  • > it is exactly a researcher's purpose to do the risky things that may not work

    Maybe at university, but not at a trillion dollar company. That job as chief scientist is leading risky things that will work to please the shareholders.

    • They knew what Yann LeCun was when they hired him. If anything, those brilliant academics who have done what they're told and loyally pursued corporate objectives the way the corporation wanted (e.g. Karpathy when he was at Tesla) haven't had great success either.

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    • > risky things that will work

      Things known to work are not risky. Risky things can fail by definition.

    • “Risky things that will work” - contradiction in terms. If companies only did things they knew would work, we probably still wouldn’t have microchips.

      Also, like… it’s Facebook. It has a history of ploughing billions into complete nonsense (see metaverse). It is clearly not particularly risk averse.

LLMs and Diffusion solve a completely different problem than world models.

If you want to predict future text, you use an LLM. If you want to predict future frames in a video, you go with Diffusion. But what both of them lack is object permanence. If a car isn't visible in the input frame, it won't be visible in the output. But in the real world, there are A LOT of things that are invisible (image) or not mentioned but only implied (text) that still strongly affect the future. Every kid knows that when you roll a marble behind your hand, it'll come out on the other side. But LLMs and Diffusion models routinely fail to predict that, as for them the object disappears when it stops being visible.

Based on what I heard from others, world models are considered the missing ingredient for useful robots and self-driving cars. If that's halfway accurate, it would make sense to pour A LOT of money into world models, because they will unlock high-value products.

  • Sure, if you only consider the model they have no object permanence. However you can just put your model in a loop, and feed the previous frame into the next frame. This is what LLM agent engineers do with their context histories, and it's probably also what the diffusion engineers do with their video models.

    Messing with the logic in the loop and combining models has an enormous potential, but it's more engineering than researching, and it's just not the sort of work that LeCun is interested in. I think the conflict lies there, that Facebook is an engineering company, and a possible future of AI lies in AI engineering rather than AI research.

  • I think World models is way to go for Super Intelligence. One of teh patent i saw already going in this direction for Autonomous mobility is https://patents.google.com/patent/EP4379577A1 where synthetic data generation (visualization) is missing step in terms of our human intelligence.

    • This is the first time I have heard of world models. Based on my brief reading it does look like this is the idea model for autonomous driving. I wonder if the self driving companies are already using this architecture or something close to it.

  • I thoroughly disagree, I believe world models will be critical in some aspect for text generation too. A predictive world model you can help to validate your token prediction. Take a look at the Code World Model for example.

> but an enterprise like Facebook can't have their top researcher work on risky things when there's surefire paths to success still available.

Bell Labs

> I think LeCun is underestimating the impact that LLM's and Diffusion models

No, I think hes suggesting that "world models" are more impactful. The issue for him inside meta is that there is already a research group looking at that, and are wildly more successful (in terms of getting research to product) and way fucking cheaper to run than FAIR.

Also LeCun is stuck weirdly in product land, rather than research (RL-R) which means he's not got the protection of Abrash to isolate him from the industrial stupidity that is the product council.

> Facebook can't have their top researcher work on risky things when there's surefire paths to success still available.

How did you determine that "surefire paths to success still available"? Most academics agree that LLMs (or LLMs alone) are not going to lead us to AGI. How are you so certain?

  • I don't believe we need more academic research to achieve AGI. The sort of applications that are solving the recent AGI challenges are just severely resource constrained AGI. The only difference between those systems and human intelligence are resources and incentives.

    Not that I believe AGI is the measure of success, there's probably much more efficient ways to achieve company goals than simulating humans.

Unless I've missed a few updates, much of the JEPA stuff didn't really bear a lot of fruit in the end.

  • I don't think he's given up on it.

    How many decades did it take for neural nets to take off?

    The reason we're even talking about LeCun today is because he was early in seeing the promise of neural nets and stuck with it through the whole AI winter when most people thought it was a waste of time.

>the huge impact they're already having

In the software development world yes, outside of that, virtually none. Yes, you can transcribe a video call in Office, yes, but that's not ground breaking. I dare you to list 10 impacts on different fields, excluding tech and including at least half blue collar fields and at least half white collar fields , at different levels from the lowest to the highest in the company hierarchy, that LLM/Diffusion models are having. Impact here specifically means a significant reduction of costs or a significant increase of revenue. Go on

  • I'm also not sure it even drives a ton of value in software engineering. It makes the easy part easier and the hard part harder. Typing out software in your mind was never the difficult part. Figuring out what to write, how to interpret specs in context, how to make your code work within the context of a broader whole, how to be extensible, maintainable, reliable, etc. That's hard, and LLMs really don't help.

    Even when writing, it shifts the mental burden from an easy thing (writing code) to a very hard thing (reading that code, validating it's right, hallucination free, and then refactoring it to match your teams code style and patterns).

    It's great for building a first-order approximation of a tech demo app that you then throw out and build from scratch, and auto-complete. In my experience, anyways. I'm sure others have had different experiences.

  • You already mentioned two fields they have a huge impact on, software development and NLP (this latter one the most impacted so far). Another field that comes to mind is academic research is getting an important boost as well, via semantic search or more advanced stuff like Google's biological cell model which already uncovered new treatments. I'm sure I'm missing a lot of other fields I'm less familiar with (legal, for example). But just these impacts I listed are all huge and they will indirectly have a huge impact on all other areas of human industry, it's just a matter of time. "Software will eat the world" and all that.

  • Personally, I find myself using LLMs more than Google now, even for non-development tasks. I think this shift is going to become the new normal (if it isn't already).

    • And what's the end result? All one can see is just bigger representation of those who confidently subscribe to false information and become arrogant when their validity is questioned, as the LLM writing style has convinced them it's some sort of authority. Even people on this website are so misinformed to believe that ChatGPT has developed its own reasoning, despite it being at the core an advanced learning algorithm trained on a enormous amount of human generated data.

      And let's not speak about those so deep into sloth that put it into use to deteriorate, and not augment as they claim to do, humane creative recreational activities.

      https://archive.ph/fg7HE

  • I don't think you'll find many here believing anything outside tech is worth investing into, it's schizophrenic isn't it.

not sure I agree. AI seems to be following the same 3-stage path of many inventions: innovation > adoption > diffusion. LeCun and co focus on the first, and LLMs in their current form appear to be incremental at improvements; we're still using the same basis from more than ten years ago. FB and industry are signalling a focus on harvesting the innovation and that could last - but also take - many years or decades. Your fundamental researchers are not interested (or the right people) in that position.

While I agree with your point, “Superintelligence” is a far cry from what Meta will end up delivering with Wang in charge. I suppose that, at the end of the day, it’s all marketing. What else should we expect from an ads company :?

He's quoted in OP as calling them 'useful but fundamentally limited'; that seems correct, and not at all like he's denying their utility.

Hard to tell.

The last time LeCun disagreed with the AI mainstream was when he kept working on neural net when everyone thought it was a dead end. He might be entirely right in his LLM scepticism. It's hardly a surefire path. He didn't prevent Meta from working on LLM anyway.

The issue is more than his position is not compatible with short term investors expectations and that's fatal in a company like Meta at the position LeCun occupies.

Yeah honestly I'm with the LLM people here

If you think LLMs are not the future then you need to come with something better

If you have a theoretical idea that's great, but take to at least GPT2 level first before writing off LLMs

Theoretical people love coming up with "better ideas" that fall flat or have hidden gotchas when they get to practical implementation

As Linus says, "talk is cheap, show me the code".

  • Do you? Or is it possible to acknowledge a plateau in innovation without necessarily having an immediate solution cooked-up and ready to go?

    Are all critiques of the obvious decline in physical durability of American-made products invalid unless they figure out a solution to the problem? Or may critics of a subject exist without necessarily being accredited engineers themselves?

  • >If you think LLMs are not the future then you need to come with something better

    The problem isn't LLMS, the problem is that everyone is trying to build bigger/better llms or manually code agents around LLMs. Meanwhile, projects like Mu Zero are forgotten, despite being vastly more important for things like self driving.

  • LLM's are probably always going to be the fundamental interface, the problem they solved was related to the flexibility of human languages allowing us to have decent mimikry's.

    And while we've been able to approximate the world behind the words, it's just full of hallucinations because the AI's lack axiomatic systems beyond much manually constructed machinery.

    You can probably expand the capabilties by attaching to the front-end but I suspect that Yann is seeing limits to this and wants to go back and build up from the back-end of world reasoning and then _among other things_ attach LLM's at the front-end (but maybe on equal terms with vision models that allows for seamless integration of LLM interfacing _combined_ with vision for proper autonomous systems).

    • > because the AI's lack axiomatic systems beyond much manually constructed machinery.

      Oh god, that is massively under-selling their learning ability. These models are able to extract and reply with why jokes are funny without even knowing basic vocab, yet there are pure-code models out there with lingual rules baked in from day one which still struggle with basic grammar.

      The _point_ of LLMs arguably is there ability to learn any pattern thrown at it with enough compute. With an exception to learning how logical processes work, and pure LLMs only see "time" in the sense of a paragraph begins and ends.

      At the least they have taught computers, "how to language", which in regards to how to interact with a machine is a _huge_ step forward.

      Unfortunately the financial incentives are split between agentic model usage (taking the idea of a computerised butler further), maximizing model memory and raw learning capacity (answering all problems at any time), and long-range consistency (longer ranges give better stable results due to a few reasons, but we're some way from seeing an LLM with a 128k experts and 10e18 active tokens).

      I think in terms of building the perfect monkey butler we already have most or all of the parts. With regard to a model which can dynamically learn on the fly... LLMs are not the end of the story and we need something to allow the models to more closely tie their LS with the context. Frankly the fact that DeepSeek gave us an LLM with LS was a huge leap since previous model attempts had been overly complex and had failed in training.

  • Why not both? LLM:s probably have a lot more potential than what is currently being realized but so does world models.

  • Of course the challenge with that is it's often not obvious until after quite a bit of work and refinement that something else is, in fact, better.