docs/source/en/model_doc/rembert.md
This model was released on 2020-10-24 and added to Hugging Face Transformers on 2021-07-24.
The RemBERT model was proposed in Rethinking Embedding Coupling in Pre-trained Language Models by Hyung Won Chung, Thibault Févry, Henry Tsai, Melvin Johnson, Sebastian Ruder.
The abstract from the paper is the following:
We re-evaluate the standard practice of sharing weights between input and output embeddings in state-of-the-art pre-trained language models. We show that decoupled embeddings provide increased modeling flexibility, allowing us to significantly improve the efficiency of parameter allocation in the input embedding of multilingual models. By reallocating the input embedding parameters in the Transformer layers, we achieve dramatically better performance on standard natural language understanding tasks with the same number of parameters during fine-tuning. We also show that allocating additional capacity to the output embedding provides benefits to the model that persist through the fine-tuning stage even though the output embedding is discarded after pre-training. Our analysis shows that larger output embeddings prevent the model's last layers from overspecializing to the pre-training task and encourage Transformer representations to be more general and more transferable to other tasks and languages. Harnessing these findings, we are able to train models that achieve strong performance on the XTREME benchmark without increasing the number of parameters at the fine-tuning stage.
For fine-tuning, RemBERT can be thought of as a bigger version of mBERT with an ALBERT-like factorization of the embedding layer. The embeddings are not tied in pre-training, in contrast with BERT, which enables smaller input embeddings (preserved during fine-tuning) and bigger output embeddings (discarded at fine-tuning). The tokenizer is also similar to the Albert one rather than the BERT one.
[[autodoc]] RemBertConfig
[[autodoc]] RemBertTokenizer - get_special_tokens_mask - save_vocabulary
[[autodoc]] RemBertTokenizerFast - get_special_tokens_mask - save_vocabulary
[[autodoc]] RemBertModel - forward
[[autodoc]] RemBertForCausalLM - forward
[[autodoc]] RemBertForMaskedLM - forward
[[autodoc]] RemBertForSequenceClassification - forward
[[autodoc]] RemBertForMultipleChoice - forward
[[autodoc]] RemBertForTokenClassification - forward
[[autodoc]] RemBertForQuestionAnswering - forward