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Module 3 - Lecture - Natural Language Processing 1: Definition and Tasks

Jul 8, 2025

Overview

This lecture introduces Natural Language Processing (NLP), a field of artificial intelligence focused on enabling computers to understand and generate human language, covering its main tasks, subtasks, and micro-tasks.

Introduction to Natural Language Processing (NLP)

  • NLP is a field within AI that enables computers to understand, interpret, and generate human language.
  • Unlike basic speech-to-text, NLP involves understanding meaning and emotional tone in spoken or written language.

Main Tasks in NLP

  • Natural Language Understanding (NLU): Comprehending user intent and meaning, e.g., voice assistants detecting homophones.
  • Natural Language Translation: Automatically converting text or speech between languages.
  • Natural Language Generation (NLG): Producing human-like language from data or intent, seen in chatbots and automated product descriptions.

Subtasks in NLP

  • Summarization: Creating concise summaries of long or complex documents.
  • Question Answering: Responding to user questions by extracting or computing answers.
  • Information Extraction: Identifying structured data (like entities or events) from unstructured text.
  • Sentiment Analysis: Detecting the emotional tone or polarity of text.
  • Semantic Analysis: Determining the meaning conveyed by text.
  • Auto-Categorization: Classifying documents into categories for further processing.

Information Extraction Details

  • Information extraction converts large amounts of unstructured text (like contracts or logs) into structured, searchable databases.
  • This involves identifying entities (people, companies), events, and relationships within documents.

Micro-Tasks in NLP

  • Part-of-Speech Tagging: Labeling each word with its grammatical role.
  • Parsing: Analyzing sentence structure as a tree for understanding relationships.
  • Sentence Boundary Detection: Identifying where sentences begin and end.
  • Word Boundary Detection: Finding word divisions, especially challenging in languages without spaces (e.g., Chinese).
  • Named Entity Recognition: Detecting specific entities such as names, places, or products in text.
  • Topic Segmentation: Dividing documents into topics or sections.
  • Automatic Summarization: Producing brief overviews of longer documents.
  • Discourse Analysis: Understanding conversational flow and context.

Applications and Implications

  • NLP automates tasks involving reading/listening, searching for information, and composing responses.
  • Professions ripe for NLP automation include customer support, law, and counseling.

Key Terms & Definitions

  • Natural Language Processing (NLP) — AI field dealing with interaction between computers and human languages.
  • Natural Language Understanding (NLU) — Task of comprehending the meaning of language.
  • Natural Language Generation (NLG) — Automated creation of human-like language output.
  • Information Extraction — Pulling structured data from unstructured text.
  • Sentiment Analysis — Identifying the emotional tone of text.
  • Named Entity Recognition — Detecting specific names or key domain entities in text.

Action Items / Next Steps

  • Review the distinctions between NLP main tasks, subtasks, and micro-tasks.
  • Prepare for deeper discussions on information extraction, sentiment analysis, and semantic analysis in upcoming lectures.