Book Image

Natural Language Processing with Flair

By : Tadej Magajna
Book Image

Natural Language Processing with Flair

By: Tadej Magajna

Overview of this book

Flair is an easy-to-understand natural language processing (NLP) framework designed to facilitate training and distribution of state-of-the-art NLP models for named entity recognition, part-of-speech tagging, and text classification. Flair is also a text embedding library for combining different types of embeddings, such as document embeddings, Transformer embeddings, and the proposed Flair embeddings. Natural Language Processing with Flair takes a hands-on approach to explaining and solving real-world NLP problems. You'll begin by installing Flair and learning about the basic NLP concepts and terminology. You will explore Flair's extensive features, such as sequence tagging, text classification, and word embeddings, through practical exercises. As you advance, you will train your own sequence labeling and text classification models and learn how to use hyperparameter tuning in order to choose the right training parameters. You will learn about the idea behind one-shot and few-shot learning through a novel text classification technique TARS. Finally, you will solve several real-world NLP problems through hands-on exercises, as well as learn how to deploy Flair models to production. By the end of this Flair book, you'll have developed a thorough understanding of typical NLP problems and you’ll be able to solve them with Flair.
Table of Contents (15 chapters)
1
Part 1: Understanding and Solving NLP with Flair
6
Part 2: Deep Dive into Flair – Training Custom Models
11
Part 3: Real-World Applications with Flair

Chapter 4: Sequence Tagging

Sequence tagging (or sequence labeling) refers to a set of Natural Language Processing (NLP) tasks that assign labels or tags to tokens or other units of text. When the tags are named entities, we are then dealing with named entity recognition (NER). When the tags are parts of speech, this task is called part-of-speech (PoS) tagging. Unlike embeddings that are trained in an unsupervised manner, sequence taggers are trained using supervised training techniques, making them easier to evaluate and compare.

Sequence tagging is a field where Flair truly shines. Flair uses the ingenuity of Flair embeddings (explained in the previous chapter) to achieve state-of-the-art results across many different sequence tagging tasks and languages.

In this chapter, we are going to briefly explain how sequence taggers work in Flair. This will allow us to fully understand the inner workings as we cover NER, PoS tagging, chunking, and other sequence tagging techniques found...