Book Image

Natural Language Processing and Computational Linguistics

By : Bhargav Srinivasa-Desikan
Book Image

Natural Language Processing and Computational Linguistics

By: Bhargav Srinivasa-Desikan

Overview of this book

Modern text analysis is now very accessible using Python and open source tools, so discover how you can now perform modern text analysis in this era of textual data. This book shows you how to use natural language processing, and computational linguistics algorithms, to make inferences and gain insights about data you have. These algorithms are based on statistical machine learning and artificial intelligence techniques. The tools to work with these algorithms are available to you right now - with Python, and tools like Gensim and spaCy. You'll start by learning about data cleaning, and then how to perform computational linguistics from first concepts. You're then ready to explore the more sophisticated areas of statistical NLP and deep learning using Python, with realistic language and text samples. You'll learn to tag, parse, and model text using the best tools. You'll gain hands-on knowledge of the best frameworks to use, and you'll know when to choose a tool like Gensim for topic models, and when to work with Keras for deep learning. This book balances theory and practical hands-on examples, so you can learn about and conduct your own natural language processing projects and computational linguistics. You'll discover the rich ecosystem of Python tools you have available to conduct NLP - and enter the interesting world of modern text analysis.
Table of Contents (22 chapters)
Title Page
Copyright and Credits
Packt Upsell
Contributors
Preface
Index

Training our own POS-taggers


The prediction done by spaCy's models with regard to its POS-tag are statistical predictions; unlike, say, whether or not it is a stop word, which is just a check against a list of words. If it is a statistical prediction, this means that we can train a model for it to perform better predictions or predictions that are more relevant to the dataset we are intending to use it on. Here, better isn't meant to be taken too literally – the current spaCy model already comes to 97% in terms of tagging accuracy.

Before we dive in deep into our training process, let's clarify a few commonly used terms when it comes to machine learning, and machine learning for text.

Training - the process of teaching your machine learning model how to make the right prediction. In text analysis, we do this by providing classified data to the model. What does this mean? In the setting of POS-tagging, it would be a list of words and their tagged POS. This labeled information is then used to...