Fine-tuning BERT for Similarity Search

Photo Credit Synopsis I have the task of finding similar entries among 8,000+ pieces of news, using their title and edited short descriptions in Traditional Chinese. I tried LASER[1] first but later found Universal Sentence Encoder[2] seemed to work slightly better. Results from these unsupervised approaches are already acceptable, but still have occasional confusion and hiccups. Not entirely satisfied with the unsupervised approaches, I collected and annotated 2,000 pairs of news and fine-tuned the BERT model on this dataset. This supervised approach is visibly better than the unsupervised one. And it’s also quite sample-efficient. Three hundred and fifty training example is already enough to beat Universal Sentence Encoder by a large margin. ...

November 28, 2019 · Ceshine Lee

Zero Shot Cross-Lingual Transfer with Multilingual BERT

Photo Credit Synopsis Do you want multilingual sentence embeddings, but only have a training dataset in English? This post presents an experiment that fine-tuned a pre-trained multilingual BERT model(“BERT-Base, Multilingual Uncased” [1][2]) on monolingual(English) AllNLI dataset[4] to create sentence embeddings model(that maps a sentence to a fixed-size vector)[3]. The experiment shows that the fine-tuned multilingual BERT sentence embeddings have generally better performance (i.e. lower error rates) over baselines in a multilingual similarity search task (Tatoeba dataset[5]). However, the error rates are still significantly higher than the ones from specialized sentence embedding models trained with multilingual datasets[5]. ...

September 24, 2019 · Ceshine Lee