Are Pre-trained Language Models Aware of Phrases? Simple but Strong Baselines for Grammar Induction

Understand

With the recent success and popularity of pre-trained language models (LMs) in natural language processing, there has been a rise in efforts to understand their inner workings.

• In line with such interest, we propose a novel method that assists us in investigating the extent to which pre-trained LMs capture the syntactic notion of constituency.
• Our method provides an effective way of extracting constituency trees from the pre-trained LMs without training.
• In addition, we report intriguing findings in the induced trees, including the fact that pre-trained LMs outperform other approaches in correctly demarcating adverb phrases in sentences.