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Can LLMs learn from a single example?

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Re: Can LLMs learn from a single example?

#101
Could this be an artifact of just not reshuffling the dataset and how the weight regime is? What if you reversed the dataset in the second epoch, under the memory hypothesis the training loss would not plummet if it has not learnt anything during the epoch after the first 10%. Yes?

The report mentions there is no reshuffling: > We’re not re-shuffling the dataset at the start of the epoch, so those first batches of the second epoch are when the learning rate was still warming up.

Re: Can LLMs learn from a single example?

#102
post #30

Earlier quoted context omitted.

Hi Jeremy, always a fan of your work! Just a technical note since it falls under my domain of expertise (astronomy) -- the example about MOND described here should actually have choice (E) as the correct answer!

As it happens I dug into this question in some detail a couple of weeks ago when analysing the dataset, including carefully reading the wikipedia page which the question comes from. AFAICT both D and E are kinda correct, but E isn't quite right because MOND doesn't entirely "eliminate the observed missing baryonic mass", but rather just reduces it from a factor of 10 to 2. Is that not correct? (Of course I fully acce…

Fascinating! I dug into the Wikipedia article, which cites a Scholarpedia article; the LLM answer seems to originate from a reference to this sentence [1]:

> So, MOND reduces the discrepancy in clusters at these radii to only a factor of ∼2−3 (Sanders, 1999; Ettori, et al., 2019)

So I think you're right, and today I learned something! I also checked if Stacy McGaugh had weighed in on this particular subject, and it seemed like there is still an issue for clusters [2], although interestingly the issue isn't mentioned in his latest blog post that summarizes the strengths/weaknesses with MOND [3]. Anyway, thanks for humoring me for a bit.

[1] http://www.scholarpedia.org/article/The_MOND_paradigm_of_mod... [2] https://tritonstation.com/2021/02/05/the-fat-one-a-test-of-s... [3] https://tritonstation.com/2023/06/27/checking-in-on-troubles...

Re: Can LLMs learn from a single example?

#103

Do people really use the phrase “over confident” in this way? It is very misleading. What is happening is called “over fitting”. Think of data as dots. A model that generalizes well will create as simple of a function as possible that fits the training data points pretty well. But keep training and parameters will often get very large, creating huge up and down swings in the function curve, far outside the actual dat…

I do think it’s a form of overfitting - loss on the training set improved while loss on the validation set got worse. However, it’s not the common form of overfitting, where accuracy on the validation set gets worse. In this case, accuracy on the validation data set continued to improve. But when it was wrong, it gave a higher confidence in its wrong answer than before. e.g. before it may have incorrectly thought the answer was X, with 60% confidence, now it still thinks the answer is X, but with higher confidence, say 70%.

I do think it’s a form of overfitting, but a weird one. Overconfidence seems like a good, more specific term to me.

Re: Can LLMs learn from a single example?

#104
I’m no expert on LLMs, but I don’t find this super surprising from a general ML point of view:

You have a generative model with billions of parameters that already assigns some probability mass to your (fine-tuning) samples. Now you compute a gradient that increases that probability mass, and take a step in the gradient’s direction. Essentially the OP is surprised that this significantly increases the probability mass of the samples under the model.

I’m not very surprised. The generative model is enormously over-parameterized and already assigns some probability mass to the (fine-tuning) samples. It would be surprising to me if there wasn’t a direction in this billion-dimensional parameter space that rapidly increases the probability of the relatively few samples.

Re: Can LLMs learn from a single example?

#105

That's intriguing. But what I want to see is if that one example can change the whole web of knowledge previously established. So, for example, if we finetune the model with a sentence like "Scientists discovered that a type of antigen can make a host immune to HIV" will it then be able to infer that "mRNA vaccines are a valid preventive approach to AIDS since they may be able to express a type of resistance known to…

That would be impressive and surprising. Humans aren’t capable of that.

> Humans aren’t capable of that.

Why do you say so? We casually call it "connecting the dots". It's like during the Oppenheimer movie when after the first demonstration of Uranium splitting people thought "oh, we can do a bomb with that".

Re: Can LLMs learn from a single example?

#106
post #30

Earlier quoted context omitted.

Hi Jeremy, always a fan of your work! Just a technical note since it falls under my domain of expertise (astronomy) -- the example about MOND described here should actually have choice (E) as the correct answer!

As it happens I dug into this question in some detail a couple of weeks ago when analysing the dataset, including carefully reading the wikipedia page which the question comes from. AFAICT both D and E are kinda correct, but E isn't quite right because MOND doesn't entirely "eliminate the observed missing baryonic mass", but rather just reduces it from a factor of 10 to 2. Is that not correct? (Of course I fully acce…

I believe neither MOND nor Condensed Dark Matter are theories exactly, so much as they are schemata for classes of theories. Both are struggling to produce a verified theory that accounts for all observations, and while the latter is much more widely regarded as likely being correct, MOND has not been conclusively falsified to everyone's satisfaction. I would guess that there are, at least in principle, MOND theories which work for galaxy clusters but have residual discrepancies when applied to galaxies.

If this is so, then a multi-choice question which conflates one particular MOND theory for MOND itself, and which depends on the specifics of that particular theory for selecting the 'correct' answer, is problematic: for one thing, it may make selecting the 'correct' answer more difficult for a student who has specific knowledge about the topic. This is just one of several problems with multi-choice questions, though, fortunately, it does not seem to have any bearing on the very interesting phenomenon you have discovered.

Re: Can LLMs learn from a single example?

#107
post #97

Probably unrelated, but I tried to get ChatGPT to write me some code to programmatically control the details of a column filter in an Excel spreadsheet in PowerShell. Nothing it tried worked, it got close, but it didn't work. Finally I found some C# code that fixed the problem, and I pasted that code into ChatGPT, asked it to read it, and then fix the problem in PowerShell. It said it understood the solution, updated…

Interesting anecdote. I think there's a common theme with current LLMs, that people focus unreasonably much on "knowledge retrieval" from the models (1) and under-hype and under-appreciate the "language model" part.

These things are really easy to anthropomize, partly because they are good at "talking" and "articulating". So good that we tend to just accept that magical, enormous feat of statistical engineering as a trivial building block. But it's a brick made of gold.

Translating (from natural language to code, from text to audio, from image to image, one natural language to another), editing, summarizing, expanding/extrapolating is what these models do.

The inherent "knowledge" is just context.

(1) Vector embedding is in my view a little different - it's a form of semantic cataloging (akin to Dewy decimal) - and certainly enables search.

But "data retrieval" (who was us president in 1984) directly from the models isn't really all that interesting IMNHO.

Re: Can LLMs learn from a single example?

#108
"Can LLMs learn from a single example"?

Sure. Neural nets in general can: after they've been trained on billions of examples first.

It really helps if they've previously seen the same or similar "single example". Which, let's be fair, the larger the training data, the higher the chances they have.

>> This seemed, at first, quite impossible. It would imply that the model was learning to recognise inputs from just one or two examples

To be more precise: the article is talking about fine-tuning a pre-trained LLM, so that's a-few-billion-plus-one-or-two examples.

Btw, what model was that? The article doesn't say.

Re: Can LLMs learn from a single example?

#109
post #2

Thank you for posting this to HN! :D I'm one of the authors of this post -- Johno & I found it really interesting looking into this curious issue of rapid memorization from LLMs. I've been working with neural nets for 30 years, and fine-tuning language models since 2017, and this behavior is most surprising to me! Other folks have seen it in LLMs too, although I haven't seen a analysis of this kind before (although w…

Essentially it does processing by gru's ?. So it should be able to learn quickly, i gave it an angular 12 chapter and it could fix some syntax bugs. maybe learn by prompting, and by techniques as used in those image generators, where people can add custom specializations over the network. (ea become excellent in angular 16 and 18) when is the language cut off going away? for rapid updating languages, or areas such as blender 3d, where api's change rapidly.

Re: Can LLMs learn from a single example?

#110

Do people really use the phrase “over confident” in this way? It is very misleading. What is happening is called “over fitting”. Think of data as dots. A model that generalizes well will create as simple of a function as possible that fits the training data points pretty well. But keep training and parameters will often get very large, creating huge up and down swings in the function curve, far outside the actual dat…

If we are considering the function to be the neural network with an argmax applied to the output probabilities, it's not overfitting at all. Its classification accuracy over unseen data (validation set) continues to improve.

The issue here is one of calibration: https://en.m.wikipedia.org/wiki/Calibration_(statistics). That is, the output probabilities of the neural network do not reflect the true (observed) probabilities. If it is systematically underestimating the probabilities, it is termed "underconfident", and if overestimating the probabilities, "overconfident".

Note that in these cases, it may still be improving as a classifier on unseen data, while still showing higher validation loss as calibration degrades.

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