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There Will Be a Scientific Theory of Deep Learning

arxiv.org

121–130 of 179 posts

Re: There Will Be a Scientific Theory of Deep Learning

#121
post #14

Earlier quoted context omitted.

The inflection point was 2012, when AlexNet [0], a deep convolutional neural net, achieved a step-change improvement in the ImageNet classification competition. After seeing AlexNet’s results, all of the major ML imaging labs switched to deep CNNs, and other approaches almost completely disappeared from SOTA imaging competitions. Over the next few years, deep neural networks took over in other ML domains as well. The…

Comparing Deep Learning with neuroscience may turn out to be erroneous. They may be orthogonal. The brain likely has more in common with Reservoir Computing (sans the actual learning algorithm) than Deep Learning. Deep Learning relies on end to end loss optimization, something which is much more powerful than anything the brain can be doing. But the end-to-end limitation is restricting, credit assignment is a big pro…

Modern systems like Nano Banana 2 and ChatGPT Images 2.0 are very close to "just use Photoshop directly" in concept, if not in execution.

They seem to use an agentic LLM with image inputs and outputs to produce, verify, refine and compose visual artifacts. Those operations appear to be learned functions, however, not an external tool like Photoshop.

This allows for "variable depth" in practice. Composition uses previous images, which may have been generated from scratch, or from previous images.

Re: There Will Be a Scientific Theory of Deep Learning

#122

Earlier quoted context omitted.

Comparing Deep Learning with neuroscience may turn out to be erroneous. They may be orthogonal. The brain likely has more in common with Reservoir Computing (sans the actual learning algorithm) than Deep Learning. Deep Learning relies on end to end loss optimization, something which is much more powerful than anything the brain can be doing. But the end-to-end limitation is restricting, credit assignment is a big pro…

If you think a 2 year old is doing deep learning, you're probably wrong. But if you think natural selection was providing end to end loss optimization, you might be closer to right. An _awful lot_ of our brain structure and connectivity is born, vs learned, and that goes for Mice and Men.

Why not both? A pre-trained LLM has an awful lot of structure, and during SFT, we're still doing deep learning to teach it further. Innate structure doesn't preclude deep learning at all.

There's an entire line of work that goes "brain is trying to approximate backprop with local rules, poorly", with some interesting findings to back it.

Now, it seems unlikely that the brain has a single neat "loss function" that could account for all of learning behaviors across it. But that doesn't preclude deep learning either. If the brain's "loss" is an interplay of many local and global objectives of varying complexity, it can be still a deep learning system at its core. Still doing a form of gradient descent, with non-backpropagation credit assignment and all. Just not the kind of deep learning system any sane engineer would design.

Re: There Will Be a Scientific Theory of Deep Learning

#123

Earlier quoted context omitted.

Gradient boosting handles tabular data better than neural networks, often because the structure is simpler, and it becomes more of an issue to deal with the noise. You can do like-to-like comparisons between them for unstructured data like images, audio, video, text, and a well-designed NN will mop the floor with gradient boosting. This is because to handle that sort of data, you need to encode some form of bias arou…

Would you agree/disagree with the following: - It's not gradient boosting per se that's good on tabular data, it's trees. Other fitting methods with trees as the model are also usually superior to NNs on tabular data. - Trees are better on tabular data because they encode a useful inductive bias that NNs currently do not. Just like CNNs or ViTs are better on images because they encode spatial locality as an inductive…

Absolutely agree on both counts. Gradient boosting is the most commonly known and most successful variant, but it's the decision tree structure that is the underlying architecture there. Decision trees don't have the same "implicit training bias" phenomenon that neural networks have though, so all of this is just model bias in the classical statistical sense.

Re: There Will Be a Scientific Theory of Deep Learning

#124

Earlier quoted context omitted.

Ok but it's already known that you shouldn't initialize your network parameters to a single constant and instead initialize the parameters with random numbers.

The model can converge towards such a state even if randomly initialized.

Both you and the comment above are correct; initializing with iid elements ensures that correlations are not disastrous for training, but strong correlations are baked into the weights during training, so pretty much anything could potentially happen.

Re: There Will Be a Scientific Theory of Deep Learning

#125

Earlier quoted context omitted.

[flagged]

>Do you think grokking is consistent with implicit regularization as compression Pretty sure it's been shown that grokking requires L1 regularization which pushes model parameters towards zero. This can be viewed as compression in the sense of encoding the distribution in the fewest bits possible, which happens to correspond to better generalization.

Couldn't have said it better, although this is only for grokking with the modular addition task on networks with suitable architectures. L1 regularization is absolutely a clear form of compression. The modular addition example is one of the best cases to see the phenomenon in action.

Re: There Will Be a Scientific Theory of Deep Learning

#126
post #42

This is encouraging. The title is a bit much. "Potential points of attack for understanding what deep learning is really doing" would be more accurate but less attention-grabbing. It might lead to understanding how to measure when a deep learning system is making stuff up or hallucinating. That would have a huge payoff. Until we get that, deep learning systems are limited to tasks where the consequences of outputting…

The field is massively hampered by the wishful mnemonics and anthropomorphization of LLMs. For example, even the hallucination idea arbitrarily assigns human semantics to LLM results. By the actual mathematical principles by which LLMs work, any hallucination is another output, with no clear definition between it and every other output.

Re: There Will Be a Scientific Theory of Deep Learning

#127

Earlier quoted context omitted.

The properties that the uniform approximation theorem proves are not unique to neural networks. Any models using an infinite dimensional Hilbert space, such as SVMs with RBF or polynomial kernels, Gaussian process regression, gradient boosted decision trees, etc. have the same property (though proven via a different theorem of course). So the universal approximation theorem tells us nothing about why should expect ne…

Whenever people bring this up I like to remind them that linear interpolation is a universal function approximator.

Can you expand on that?

Re: There Will Be a Scientific Theory of Deep Learning

#128

Earlier quoted context omitted.

Would you agree/disagree with the following: - It's not gradient boosting per se that's good on tabular data, it's trees. Other fitting methods with trees as the model are also usually superior to NNs on tabular data. - Trees are better on tabular data because they encode a useful inductive bias that NNs currently do not. Just like CNNs or ViTs are better on images because they encode spatial locality as an inductive…

Absolutely agree on both counts. Gradient boosting is the most commonly known and most successful variant, but it's the decision tree structure that is the underlying architecture there. Decision trees don't have the same "implicit training bias" phenomenon that neural networks have though, so all of this is just model bias in the classical statistical sense.

Can NNs be made to be better than trees on tabular data with some further constraints, or something?

Re: There Will Be a Scientific Theory of Deep Learning

#129

As someone who works in the area, this provides a decent summary of the most popular research items. The most useful and impressive part is the set of open problems at the end, which just about covers all of the main research directions in the field. The skepticism I'm seeing in the comments really highlights how little of this work is trickling down to the public, which is very sad to see. While it can offer few mat…

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Re: There Will Be a Scientific Theory of Deep Learning

#130

As someone who works in the area, this provides a decent summary of the most popular research items. The most useful and impressive part is the set of open problems at the end, which just about covers all of the main research directions in the field. The skepticism I'm seeing in the comments really highlights how little of this work is trickling down to the public, which is very sad to see. While it can offer few mat…

We’re in a strange era where the Information-Theoretic foundations of deep learning are solidifying. The 'Why' is largely solved: it’s the efficient minimization of irreversible information loss relative to the noise floor. There is so much waste scaling models bigger and bigger when the math points to how to do it much more efficiently. One can take a great 70B model and have it run in only ~16GB with no loss in cap…

> It’s honestly a bit painful watching the AI field struggle to re-learn first principles that other disciplines have already learned.

This is my fear with software development in general. There's a hundred-year old point of view right next door that'll solve problems and I'm too incurious to see it.

I have a relative with a focus in math education that I've been stealing ideas from, and I think we'd both appreciate a look at your doc if you don't mind.

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