Book Image

Getting Started with Google BERT

By : Sudharsan Ravichandiran
Book Image

Getting Started with Google BERT

By: Sudharsan Ravichandiran

Overview of this book

BERT (bidirectional encoder representations from transformer) has revolutionized the world of natural language processing (NLP) with promising results. This book is an introductory guide that will help you get to grips with Google's BERT architecture. With a detailed explanation of the transformer architecture, this book will help you understand how the transformer’s encoder and decoder work. You’ll explore the BERT architecture by learning how the BERT model is pre-trained and how to use pre-trained BERT for downstream tasks by fine-tuning it for NLP tasks such as sentiment analysis and text summarization with the Hugging Face transformers library. As you advance, you’ll learn about different variants of BERT such as ALBERT, RoBERTa, and ELECTRA, and look at SpanBERT, which is used for NLP tasks like question answering. You'll also cover simpler and faster BERT variants based on knowledge distillation such as DistilBERT and TinyBERT. The book takes you through MBERT, XLM, and XLM-R in detail and then introduces you to sentence-BERT, which is used for obtaining sentence representation. Finally, you'll discover domain-specific BERT models such as BioBERT and ClinicalBERT, and discover an interesting variant called VideoBERT. By the end of this BERT book, you’ll be well-versed with using BERT and its variants for performing practical NLP tasks.
Table of Contents (15 chapters)
1
Section 1 - Starting Off with BERT
5
Section 2 - Exploring BERT Variants
8
Section 3 - Applications of BERT

A Lite version of BERT

In this section, we will learn about A Lite version of BERT, also known as ALBERT. One of the challenges with BERT is that it consists of millions of parameters. BERT-base consists of 110 million parameters, which makes it harder to train, and it also has a high inference time. Increasing the model size gives us good results but it puts a limitation on the computational resources. To combat this, ALBERT was introduced. ALBERT is a lite version of BERT with fewer parameters compared to BERT. It uses the following two techniques to reduce the number of parameters:

  • Cross-layer parameter sharing
  • Factorized embedding layer parameterization

By using the preceding two techniques, we can reduce the training time and inference time of the BERT model. First, let's understand how these two techniques work in detail, and then we will see how ALBERT is pre-trained.

Cross-layer parameter sharing

Cross-layer parameter sharing is an interesting method for reducing the...