These language models lack context, not just for arithmetic, but for everything. They can't parse "X * Y" for any X and Y, they've just associated the expression with the right answer for so many values of X and Y, that we get fooled into thinking they know the rules.
We get fooled into thinking they've learned the structure of the world. But they've only learned the structure of text.
At a certain point, when you have enough data, finding the actual rule is actually the easier solution than memorizing each data point. This is the key insight of deep learning.
More fundamentally, any finite neural net is either constant or linear outside the training sample,depending on the activation function. Unless you design special neurons like in the paper above, which solves this specific problem for arithmetic, but not the general problem of extrapolation.
Hence why the structure of our bodies has to include the capacity for imagination. Our brain structure does not record everything that has happened. It permits is to imagine an infinite number of things which might happen.
We do not come to understand the world by having a brain-structure isomorphic to world structure -- this is none-sense for, at least, the above reason. But also, there really isnt anything like "world structure" to be isomorphic to. Ie., brains arent HDDs.
They are, at least, simulators. I dont think we'll find anything in the brain like "leaves are green" because that is just a generated public representation of a latent-simulating-thought. There isnt much to be learned about the world from these, they only make sense to us.
That all the text of human history has associations between words is the statistical coincidence that modern NLP uses for its smoke-and-mirrors. As a theory of language it's madness.
The way that Transformers learn has more to do with their multilayering than with the transformation across any one layer. Universal approximation only describes the things the network learns across any pair of layers, but the input and output features that it learns about in the middle are only tangentially related to the training samples. You cannot predict the capabilities of a deep neural network by considering the limitations of a one-layer learner.
To what degree does the structure of text correspond to structure of the world, in the limit of a maximally descriptive text corpus? Nearly complete if not totally complete, as far as I can tell. What is left out? The subjective experience of being embodied in the world. But this subjective experience is orthogonal to the structure of the world. And so this limitation does not prevent an understanding of the structure.
The reason language makes sense to us is that it triggers the right representations. It does not make sense intrinsically, it's just a sequence of symbols.
Learning about the world requires at least causal inference, modular and compact representations such as programming languages, and much smarter learning algorithms than random search or gradient descent.
Sure, there is a lot. But let's say we want to learn what apples are. So we look at occurrences of "apple" in the text corpus, and learn that apples can be eaten, they can be sweet, sometimes they are sour, red, sometimes green, and so on.
Can apples spontaneously change size? Hmm, no idea, no mention of that in the text. Can they be used as a knife? Dunno. If I had an apple in New York 4 minutes ago, can someone else be eating the same apple in Hong Kong now? Dunno. Did apples exist in France two million years ago? Dunno. Can you drive to Saturn in an apple? Dunno.
In short, there's no actual model of what an apple is, as an object in space, connected to other objects by various relationships. If there were, the model could figure out the answers to the questions above by inheritance.
Maybe these particular questions happen to be answered correctly by PaLM. Maybe not, but the next LLM will include this comment in the training corpus.
But the reason GPT-3 and other models tend to make no sense is because their output is not constrained by reality. The text in the training corpus tends to conform to reality, but when you prompt the model with questions that nobody would ever write text about, the illusion falls away:
Q: How many eyes does a giraffe have? A: A giraffe has two eyes.
Q: How many eyes does my foot have? A: Your foot has two eyes.
Q: How many eyes does a spider have? A: A spider has eight eyes.
Q: How many eyes does the sun have? A: The sun has one eye.
Q: How many eyes does a blade of grass have? A: A blade of grass has one eye.
Q: How do you sporgle a morgle? A: You sporgle a morgle by using a sporgle.
Q: How many bonks are in a quoit? A: There are three bonks in a quoit.
Q: How many rainbows does it take to jump from Hawaii to seventeen? A: It takes two rainbows to jump from Hawaii to seventeen.
Q: Which colorless green ideas sleep furiously? A: Ideas that are colorless, green, and sleep furiously are the ideas of a sleep furiously.
Q: Do you understand these questions? A: I understand these questions.
(from https://lacker.io/ai/2020/07/06/giving-gpt-3-a-turing-test.h...)
I don't know why you think language models are fundamentally unable to deduce the knowledge of the points you mention. Much knowledge isn't explicitly stated, but is implicit and can be deduced from a collection of explicit facts. For example, apples are food, food is physical matter, physical matter is fixed in size, cannot be in two places at once, maintains its current momentum unless acted on by a force, etc. Categorization and deducing properties from an object's category is in parameter space of language models. There's no reason to think that a sufficiently large model will not land on these parameters.
>But the reason GPT-3 and other models tend to make no sense is because their output is not constrained by reality.
The issue isn't what GPT-3 can or cannot do, its about what autoregressive language models as a class are capable of. Yes, there are massive holes in GPT-3's ability to maintain coherency across wide ranges of contexts. But GPT-3's limits does not imply a limit to autoregressive language models more generally.
Because the knowledge is not there in the text, the models are not able to represent it, and as seen in the demonstration above, they don't have it.
Reduce knowledge to particular kinds of information. Gradient descent discovers information by finding parameters that correspond to the test criteria. Given a large enough data set that is sufficiently descriptive of the world, the "shape" of the world described by the data admits better and worse structures to predict the data. The organizing and association of information that we call knowledge is a part of the parameter space of LLMs. There is no reason to think such a learning process cannot find this parameter space.
So how does PaLM understand causal chains and explain jokes that it has never seen before?
But you could also just try one of these models, and see for yourself. It's not exactly subtle.
https://www.technologyreview.com/2020/08/22/1007539/gpt3-ope...
"It's pattern matching" just sounds like an excuse for why it working "doesn't really count". At this point, you are asking me to disbelieve plain evidence. I have played with these models, people I know have played with these models, I have some impression of what they're capable of. I'm not disagreeing it's "just pattern matching", whatever that means, I am asserting that "pattern matching" is Turing-complete, or rather, cognition-complete, so this is just not a relevant argument to me.
What do you think a neuron does?
>you are asking me to disbelieve plain evidence
And the errors that GPT does tend to be off-by-one errors, human errors, misunderstandings, confusions. It loses the plot. But a Markov chain never even has the plot for an instant.
GPT pattern-matches at an abstract, conceptual level. If you don't understand why that is a huge deal, I can't help you.
But the way these models are talked about is misleading. They don't "answer questions", "translate", "explain jokes", or anything of that sort. They predict missing words. Since the network is so large, and the dataset has so many examples, it can scale up the method of 1) Find a part of the network which encodes training data that is most similar to the prompt 2) Put the words from the prompt in place of the corresponding words in the encoding of the training data
i.e. pattern matching. So if it has seen a similar question to the one given in the prompt (and given that it's trained on most of the internet, it will find thousands of uncannily similar questions), it will produce a convincing answer.
How is that different from a human answering questions? A human uses pattern matching as part of the process, sure. But they also use, well, all the other abilities that together make up intelligence. They connect that meaningless symbols of the sentence to the mental representations that model the world - the ones pertaining to whatever the question is about.
If I ask a librarian "What is the path integral formulation of quantum mechanics?", and they come back with a textbook and proceed to read the answer from page 345, my reaction is not "Wow, you must be a genius physicist!", it's "Wow, you sure know where to find the right book for any question!". In the same way, I'm impressed with GPT for being a nifty search engine, but then again, Google search does a pretty good job of that already.
In my experience with language models, what they do cannot be reduced to madlibs. But that's obviously not an argument I can prove to you.
Can we agree that if the model can explain structurally novel jokes, then it must have some measure of true understanding?
If you somehow manage to invent a kind of joke never before seen in the vast training corpus, that alone would be impressive. If PaLM can then explain that joke, I will change my mind about language models, and then probably join the "NNs are magic you guys" crowd, because it wouldn't make any sense.
Of course, if we can't come up with something sufficiently novel to challenge it with, that also says something about the expected difficulty of its deployment. :-P
I guess once we find a more sample-efficient way to train transformers, it'll become easier to create a dataset where some entire genre of joke will be excluded.
> The structure of text is not the structure of the world. This thesis is mad. Its a scientific thesis. It is trivial to test it. It is trivial to wholey discred it. It's pseudoscience.
It's unclear what you even mean by that. Are the electrical impulses coming to our brain the "structure of the world"?