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...