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What happened to BERT and T5?

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Re: What happened to BERT and T5?

#61

For people like me who gave up trying to follow Arxiv ML papers 3+ years ago, articles like these are gold. I would love a Youtube channel or blog which does retrospectives on "big" papers of the last decade (those that everyone paid attention to at the time) and look at where the ideas are today.

yes. my pics of youtubers (some news, but some paper reviews too) here https://github.com/swyxio/ai-notes/blob/main/Resources/Good%...

Re: What happened to BERT and T5?

#62
post #52

For people like me who gave up trying to follow Arxiv ML papers 3+ years ago, articles like these are gold. I would love a Youtube channel or blog which does retrospectives on "big" papers of the last decade (those that everyone paid attention to at the time) and look at where the ideas are today.

All you need is uninterrupted attention

Maybe one needs additional heads of attention?

Re: What happened to BERT and T5?

#64
post #56
post #8

Earlier quoted context omitted.

Classification is just too damn convenient with LLMs.

* without already labelled training data (assuming you're referring to causal LLMs). If you have labelled training data (or semi-labelled), BERT takes the cake, both in terms of accuracy and efficiency. In fact, you can have luck with getting a CLM to generate noisy labels and then training BERT/RoBERTa on that to get a robust strong classifier.

Between my experience and arXiv papers I've read I'd say this:

Personally I am willing to label 1000-2000 documents to create a training set. It's reasonable to make about 2000 simple judgements in an 8-hour "day" so it is something you could do at work or in your spare time in a few days if you want.

You can compute an embedding and then use classical ML algorithms from scikit-learn such as the support vector machine. My recommender can train a new model in about 3 minutes and that includes building about 20 models and testing them against each other to produce a model which is well tested and probability calibrated. This process is completely industrial, can run unattended, and always makes a good model if it gets good inputs. Running it every day is no sweat.

You can also "fine-tune" a model, actually changing the parameters of the deep model. I've fine-tuned BERT family models for my recommender, it takes at least 30 minutes and the training process is not completely reliable. A reliable model builder would probably do that 20 or so times with different parameters (learning rate, how long to train the model, etc.) and pick out the best model. As it is the best models from it is about as good as my simpler models, and a bad one is worse. I can picture industrializing it but I'm not sure it's worth it. In a lot of papers people just seemed to copy a recipe from another paper and don't seem to do any model selection.

My problem is fuzzy: the answer to "Do I like this article?" could vary from day to day. If I had a more precise problem "fine tuning" might pull ahead. Some people do get a significant improvement which would make it worth it, particularly if you don't expect to retrain frequently.

I see papers where somebody does the embedding transformation but instead of pooling over the tokens (averaging the vectors) they input the vectors into an LSTM, GRU or something like that and train the recurrent model. This kind of model does great when word order matters as in sentiment analysis. I found that kind of model was easy to train in a repeatable way a decade ago so that's an option I'd consider.

Re: What happened to BERT and T5?

#65
post #56

Earlier quoted context omitted.

* without already labelled training data (assuming you're referring to causal LLMs). If you have labelled training data (or semi-labelled), BERT takes the cake, both in terms of accuracy and efficiency. In fact, you can have luck with getting a CLM to generate noisy labels and then training BERT/RoBERTa on that to get a robust strong classifier.

Between my experience and arXiv papers I've read I'd say this: Personally I am willing to label 1000-2000 documents to create a training set. It's reasonable to make about 2000 simple judgements in an 8-hour "day" so it is something you could do at work or in your spare time in a few days if you want. You can compute an embedding and then use classical ML algorithms from scikit-learn such as the support vector machin…

You're better off trying to figure out what features you like about articles that are less ambiguous as signal. You would then be able to finetune models to classify whether those features are present. Whether it's classificaton of chunks/sentences/tokens. For these, a bert model could be fine tuned to efficiently detect it.

Re: What happened to BERT and T5?

#66

Earlier quoted context omitted.

Shhh, don’t tell everybody the secret. ;-)

Lol isn't everyone doing it? That's how I bootstraped my BERT fine-tunes.

I would say everybody smart is doing that, but a lot of the dumb money in AI right now is just wrappers on the GPT API That makes for a flashy demo with no underlying substance or expertise.

Re: What happened to BERT and T5?

#67

Maybe in SOTA ml/nlp research, but in the world of building useful tools and products, BERT models are dead simple to tune, work great if you have decent training data, and most importantly are very very fast and very very cheap to run. I have a small Swiss army collection of custom BERT fine tunes that are equal or better than the best LLM and execute document classification tasks in 2.4ms. Find me an LLM that can d…

Latency, throughput and cost are still very important for many applications. Also the output of a purpose-built encoder model is preferable to natural language. Not only is it unambiguous, but scores are often an important part of the result. Last, if you need to get into some advanced methods of training, like pseudolabeling and semi-supervised learning, there’s different options and outlets for utilizing real world…

Scores are also interesting in that you can get 1.0 match on a classification task, but if the model is dog shit it’s 1.0 of dog shit.

I’m still struggling with the degree to which I want to expose raw scores to users for that reason.

On the other hand, sometimes a document that slightly above an arbitrary threshold isn’t great, or a document slightly below an arbitrary threshold may be fine.

I’m excited about how easy it is to do this stuff, as the tooling is sophisticated enough now, you don’t need to know too much about the underlying mechanisms to do things that are useful. Once you get into those very fine distinction, it’s still very difficult work.

Re: What happened to BERT and T5?

#69

> It is also worth to note that, generally speaking, an Encoder-Decoders of 2N parameters has the same compute cost as a decoder-only model of N parameters which gives it a different FLOP to parameter count ratio. Can someone explain this to me? I'm not sure how the compute costs are the same between the 2N and N nets.

You can break your sequence into two parts. One part goes through the encoder and the other goes through the decoder, so each token only goes through one transformer stack.

I think it's because most of the compute comes from the decoding, since you're doing it autoregressively, while the encoder you just feed it through once and get the embedding. So really all it's saying is that the decoder, with N parameters, is the compute bottleneck; hence encoder-decoder with N+N has similar order compute cost as decoder with N.
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