Does BERT Understand Sentiment? Leveraging Comparisons Between Contextual and Non-Contextual Embeddings to Improve Aspect-Based Sentiment Models
This work provides an incremental improvement in sentiment analysis for researchers and developers working on aspect-based sentiment classification.
This paper investigates whether BERT understands sentiment by comparing contextual BERT embeddings with generic word embeddings. They found that training a model on this comparison, and then finetuning a subset of its weights, achieves state-of-the-art results for Polarity Detection in Aspect-Based Sentiment Classification.
When performing Polarity Detection for different words in a sentence, we need to look at the words around to understand the sentiment. Massively pretrained language models like BERT can encode not only just the words in a document but also the context around the words along with them. This begs the questions, "Does a pretrain language model also automatically encode sentiment information about each word?" and "Can it be used to infer polarity towards different aspects?". In this work we try to answer this question by showing that training a comparison of a contextual embedding from BERT and a generic word embedding can be used to infer sentiment. We also show that if we finetune a subset of weights the model built on comparison of BERT and generic word embedding, it can get state of the art results for Polarity Detection in Aspect Based Sentiment Classification datasets.