  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.
