transformers/docs/source/en/model_doc/prophetnet.md

ProphetNet

Overview

The ProphetNet model was proposed in ProphetNet: Predicting Future N-gram for Sequence-to-Sequence Pre-training, by Yu Yan, Weizhen Qi, Yeyun Gong, Dayiheng Liu, Nan Duan, Jiusheng Chen, Ruofei Zhang, Ming Zhou on 13 Jan, 2020.

ProphetNet is an encoder-decoder model and can predict n-future tokens for "ngram" language modeling instead of just the next token.

The abstract from the paper is the following:

In this paper, we present a new sequence-to-sequence pretraining model called ProphetNet, which introduces a novel self-supervised objective named future n-gram prediction and the proposed n-stream self-attention mechanism. Instead of the optimization of one-step ahead prediction in traditional sequence-to-sequence model, the ProphetNet is optimized by n-step ahead prediction which predicts the next n tokens simultaneously based on previous context tokens at each time step. The future n-gram prediction explicitly encourages the model to plan for the future tokens and prevent overfitting on strong local correlations. We pre-train ProphetNet using a base scale dataset (16GB) and a large scale dataset (160GB) respectively. Then we conduct experiments on CNN/DailyMail, Gigaword, and SQuAD 1.1 benchmarks for abstractive summarization and question generation tasks. Experimental results show that ProphetNet achieves new state-of-the-art results on all these datasets compared to the models using the same scale pretraining corpus.

The Authors' code can be found here.

Usage tips

• ProphetNet is a model with absolute position embeddings so it's usually advised to pad the inputs on the right rather than the left.
• The model architecture is based on the original Transformer, but replaces the “standard” self-attention mechanism in the decoder by a main self-attention mechanism and a self and n-stream (predict) self-attention mechanism.

Resources

• Causal language modeling task guide
• Translation task guide
• Summarization task guide

ProphetNetConfig

autodoc ProphetNetConfig

ProphetNetTokenizer

autodoc ProphetNetTokenizer

ProphetNet specific outputs

autodoc models.prophetnet.modeling_prophetnet.ProphetNetSeq2SeqLMOutput

autodoc models.prophetnet.modeling_prophetnet.ProphetNetSeq2SeqModelOutput

autodoc models.prophetnet.modeling_prophetnet.ProphetNetDecoderModelOutput

autodoc models.prophetnet.modeling_prophetnet.ProphetNetDecoderLMOutput

ProphetNetModel

autodoc ProphetNetModel - forward

ProphetNetEncoder

autodoc ProphetNetEncoder - forward

ProphetNetDecoder

autodoc ProphetNetDecoder - forward

ProphetNetForConditionalGeneration

autodoc ProphetNetForConditionalGeneration - forward

ProphetNetForCausalLM

autodoc ProphetNetForCausalLM - forward