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

Flair embeddings

Flair embeddings are a special type of contextual string embeddings that model words as a sequence of characters. They are the reason behind Flair's excellent sequence tagging performance and were essentially the motivation for the introduction of the Flair NLP framework. The Contextual String Embeddings for Sequence Labeling paper, an interesting and easy read written by the original creator of Flair, explains the inner workings of Flair embeddings brilliantly. But to grasp Flair embeddings from the perspective of an NLP engineer, we only need to understand their two properties: their contextuality and character-level sequence modeling.

Understanding the contextuality of Flair embeddings

The idea behind contextual string embeddings is that each word embedding should be defined by not only its syntactic-semantic meaning but also the context it appears in. What this means is that each word will have a different embedding for every context it appears in.

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