Learn to build spell checkers and grammar correction models using Python. Explore NLP packages, POS tagging, heuristic methods, and transformer-based spellcheckers for practical use.

Spell Check and Grammar Parsing using Natural Language Processing.png

gector.tar.gz

python3.8

gector job-spa

python 3.7 (no warning)

python3.7

In this course, you’ll learn the details of spell check and grammatical error correction systems by creating them with their basic building blocks. You’ll explore natural language processing packages like NLTK, pandas, spaCy, Fuzz, GECToR, HuggingFace, and more. 

You’ll build the Norvig spellchecker and understand how modern machine learning-based spellcheckers work. This is followed by the mathematical concepts required for identifying part-of-speech (POS) tags for grammatical error checking. You’ll then implement a POS rule-based grammar checker, using a heuristic-based approach to correct grammar mistakes. Finally, you’ll learn to develop a transformer-based spellchecker using HuggingFace’s transformer libraries through a hands-on final project.

After completing this course, you’ll fully understand how modern spellcheckers and grammar correction software work and how these can be integrated into natural language corrector systems such as Grammarly.

Building Grammatical Error Correction Models with Python

The spellchecker uses probability theory to determine which word to suggest as a correction. It selects the candidate $c$ that maximizes the conditional probability $P(c|w)$, where $w$ is the original word. Mathematically we can write it as follows:


$$\underset{c \ \in \ \text{candidates}} { \text{ arg\ max}} \ P(c|w)$$


Given all of our candidate words, we are computing the probability of correcting $c$ for a word $w$. When computed for all candidates, we return the candidate $c$ with the highest probability.


If we use [Bayes' Theorem](https://www.educative.io/answers/what-is-bayes-theorem-in-ai-nlp), which states that:


$$ P(A|B) = \frac{P(A)P(B|A)}{P(B)}$$


Here, we can rewrite our conditional probability as follows:


$$\underset{c \ \in \ \text{candidates}} { \text{ arg\ max}} \ P(c) P(w|c).$$


Get introduced to the Norvig spellchecker and its basic components. 

Norvig Spellchecker

Get introduced to the Norvig spellchecker and its basic components.

Introduction

Edit Distance

Basic Spellchecker

Modern Spell Check Methods

Part-of-Speech Tagging

Basic Grammatical Error Checking

Modern Grammar Error Correction Methods

Project: Simple Transformer

Conclusion

Auto-Tagging System for Content Categorization

Norvig Spellchecker

Overview