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--- |
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license: apache-2.0 |
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datasets: |
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- wikimedia/wikipedia |
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- bookcorpus |
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- nomic-ai/nomic-bert-2048-pretraining-data |
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language: |
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- en |
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inference: false |
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--- |
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# nomic-bert-2048: A 2048 Sequence Length Pretrained BERT |
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`nomic-bert-2048` is a BERT model pretrained on `wikipedia` and `bookcorpus` with a max sequence length of 2048. |
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We make several modifications to our BERT training procedure similar to [MosaicBERT](https://www.databricks.com/blog/mosaicbert). |
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Namely, we add: |
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- Use [Rotary Position Embeddings](https://arxiv.org/pdf/2104.09864.pdf) to allow for context length extrapolation. |
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- Use SwiGLU activations as it has [been shown](https://arxiv.org/abs/2002.05202) to [improve model performance](https://www.databricks.com/blog/mosaicbert) |
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- Set dropout to 0 |
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We evaluate the quality of nomic-bert-2048 on the standard [GLUE](https://gluebenchmark.com/) benchmark. We find |
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it performs comparably to other BERT models but with the advantage of a significantly longer context length. |
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| Model | Bsz | Steps | Seq | Avg | Cola | SST2 | MRPC | STSB | QQP | MNLI | QNLI | RTE | |
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|-------------|-----|-------|-------|----------|----------|----------|------|------|------|------|------|------| |
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| NomicBERT | 4k | 100k | 2048 | 0.84 | 0.50 | 0.93 | 0.88 | 0.90 | 0.92 | 0.86 | 0.92 | 0.82 | |
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| RobertaBase | 8k | 500k | 512 | 0.86 | 0.64 | 0.95 | 0.90 | 0.91 | 0.92 | 0.88 | 0.93 | 0.79 | |
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| JinaBERTBase| 4k | 100k | 512 | 0.83 | 0.51 | 0.95 | 0.88 | 0.90 | 0.81 | 0.86 | 0.92 | 0.79 | |
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| MosaicBERT | 4k | 178k | 128 | 0.85 | 0.59 | 0.94 | 0.89 | 0.90 | 0.92 | 0.86 | 0.91 | 0.83 | |
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## Pretraining Data |
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We use [BookCorpus](https://huggingface.co/datasets/bookcorpus) and a 2023 dump of [wikipedia](https://huggingface.co/datasets/wikimedia/wikipedia). |
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We pack and tokenize the sequences to 2048 tokens. If a document is shorter than 2048 tokens, we append another document until it fits 2048 tokens. |
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If a document is greater than 2048 tokens, we split it across multiple documents. We release the dataset [here](https://huggingface.co/datasets/nomic-ai/nomic-bert-2048-pretraining-data/) |
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# Usage |
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```python |
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from transformers import AutoModelForMaskedLM, AutoConfig, AutoTokenizer, pipeline |
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tokenizer = AutoTokenizer.from_pretrained('bert-base-uncased') # `nomic-bert-2048` uses the standard BERT tokenizer |
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config = AutoConfig.from_pretrained('nomic-ai/nomic-bert-2048', trust_remote_code=True) # the config needs to be passed in |
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model = AutoModelForMaskedLM.from_pretrained('nomic-ai/nomic-bert-2048',config=config, trust_remote_code=True) |
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# To use this model directly for masked language modeling |
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classifier = pipeline('fill-mask', model=model, tokenizer=tokenizer,device="cpu") |
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print(classifier("I [MASK] to the store yesterday.")) |
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``` |
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To finetune the model for a Sequence Classification task, you can use the following snippet |
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```python |
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from transformers import AutoConfig, AutoModelForSequenceClassification |
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model_path = "nomic-ai/nomic-bert-2048" |
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config = AutoConfig.from_pretrained(model_path, trust_remote_code=True) |
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# strict needs to be false here since we're initializing some new params |
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model = AutoModelForSequenceClassification.from_pretrained(model_path, config=config, trust_remote_code=True, strict=False) |
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``` |
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# Join the Nomic Community |
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- Nomic: [https://nomic.ai](https://nomic.ai) |
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- Discord: [https://discord.gg/myY5YDR8z8](https://discord.gg/myY5YDR8z8) |
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- Twitter: [https://twitter.com/nomic_ai](https://twitter.com/nomic_ai) |
