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Unit 10 Context-free grammar

Learning outcomes

By the end of this unit you should:

  • Understand the fundamentals of context-free grammars and their formal properties
  • Be able to design and construct grammar rules for natural language structures
  • Compare and evaluate different parsing algorithms and their computational complexity
  • Apply syntactic analysis techniques to real-world language data
  • Implement grammar induction methods to learn patterns from corpora
  • Generate natural language text using context-free grammar frameworks
  • Integrate parsing capabilities into advanced NLP applications

Activity 1: Grammar theory fundamentals

Context-free grammars (CFGs) provide a mathematical framework for describing the syntactic structure of natural languages. Understanding their formal properties is essential for computational linguistics applications.

Interactive Grammar Explorer

Explore different types of grammar rules and their derivations:

Production Rules:

Grammar Properties Analyzer

Analyze the formal properties of your grammar:

Activity 2: Interactive grammar builder

Build your own context-free grammar by defining production rules and testing them with sample sentences. This hands-on activity helps you understand how grammar rules interact to generate language structures.

Grammar Rule Builder

Add New Rule:
Current Grammar Rules:
S → NP VP
NP → Det N
VP → V NP
Det → 'the' | 'a'
N → 'cat' | 'dog' | 'mat'
V → 'sits' | 'runs' | 'jumps'
Test Your Grammar:
Grammar Validation:

Activity 3: Parsing algorithm comparison

Compare different parsing algorithms including top-down recursive descent, bottom-up shift-reduce, and chart parsing. Understand their strengths, weaknesses, and computational complexity.

Algorithm Performance Simulator

Activity 4: Syntactic analysis laboratory

Apply syntactic analysis to real-world text data. Explore constituency parsing, dependency parsing, and syntactic feature extraction from various text types including news articles, academic papers, and social media posts.

Text Analysis Workbench

Constituency Parsing

Activity 5: Grammar induction challenge

Learn grammar rules automatically from text corpora using computational methods. Explore different induction algorithms and understand how machines can discover linguistic patterns without explicit programming.

Grammar Learning Laboratory

Training Corpus:
Induction Settings:
2

Activity 6: Natural language generation

Generate natural language text using context-free grammar rules. Explore different generation strategies including random generation, template-based generation, and semantically-guided text production.

Text Generation Studio

Random Sentence Generation
3

Activity 7: Advanced parsing applications

Integrate context-free grammar parsing into real-world NLP applications including machine translation preprocessing, question answering systems, dialogue management, and automated essay scoring.

Application Integration Hub

Syntax-Aware Translation
Unit Progress

Grammar Fundamentals: ✓

Interactive Builder: ✓

Algorithm Comparison: ✓

Syntactic Analysis: ✓

Grammar Induction: ✓

Text Generation: ✓

Advanced Applications: ✓

Skills Developed

Context-Free Grammar Design

Parsing Algorithm Understanding

Syntactic Feature Analysis

Grammar Learning Methods

Text Generation Techniques

Real-world NLP Integration

Course Completion

Congratulations!

You have completed all 10 units of Python for NLP

Advanced parsing techniques

Probabilistic grammars

Neural parsing models

Continue exploring computational linguistics!