Learned in Translation: Contextualized Word Vectors
Computer vision has benefited from initializing multiple deep layers with weights pretrained on large supervised training sets like ImageNet. Natural language processing (NLP) typically sees initialization of only the lowest layer of deep models with pretrained word vectors. In this paper, we use a deep LSTM encoder from an attentional sequence-to-sequence model trained for machine translation (MT) to contextualize word vectors. We show that adding these context vectors (CoVe) improves performance over using only unsupervised word and character vectors on a wide variety of common NLP tasks: sentiment analysis (SST, IMDb), question classification (TREC), entailment (SNLI), and question answering (SQuAD). For fine-grained sentiment analysis and entailment, CoVe improves performance of our baseline models to the state of the art.
This paper proposes to pretrain sentence encoders for various NLP tasks using machine translation data. In particular, the authors propose to share the whole pretrained sentence encoding model (an LSTM with attention), not just the word embeddings as have been done to great success over the last few years. Evaluations are carried out on sentence classification tasks (sentiment, entailment & question classification) as well as question answering. In all evaluations, the pretrained model outperforms a randomly initialized model with pretrained GloVe embeddings only.
This is a good paper that presents a simple idea in a clear, easy to understand manner. The fact that the pretraining helps all tasks across the board is an important finding, and therefore I recommend this paper for publication.
Are the authors going to release their pretrained models?
The authors should cite https://arxiv.org/pdf/1611.02683.pdf, where the encoders are pretrained as language models.