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Dinesh Kumar, Lovely Professional University Unit 11: Natural Language Processing

Unit 11: Natural Language Processing Notes

CONTENTS
Objectives
Introduction
11.1 Natural Language Processing – Overview

11.1.1 Evaluation in NLP
11.1.2 Tasks and Limitations of NLP
11.1.3 Sub-problems of NLP

11.2 Steps in Natural Language Processing
11.2.1 Morphological Analysis
11.2.2 Syntactic Processing
11.2.3 Semantic Analysis
11.2.4 Discourse and Pragmatic Processing

11.3 Spell Checking
11.4 Summary
11.5 Keywords

11.6 Review Questions
11.7 Further Readings

Objectives

After studying this unit, you will be able to:
 Understand the concept of natural language processing

 Identify the steps in natural language processing
 Discuss the spell checking

Introduction

Natural language processing is a field of computer science concerned with the interactions
between computers and human (natural) languages. Natural language generation systems convert
information from computer databases into readable human language. Natural language
understanding systems convert samples of human language into more formal representations
that are easier for computer programs to manipulate. Many problems within NLP apply to both
generation and understanding; for example, a computer must be able to model morphology
(the structure of words) in order to understand an English sentence, but a model of morphology
is also needed for producing a grammatically correct English sentence. NLP has significant
overlap with the field of computational linguistics, and is often considered a sub-field of artificial
intelligence. The term natural language is used to distinguish human languages (such as Spanish,
Swahili or Swedish) from formal or computer languages (such as C++, Java or LISP). Although
NLP may encompass both text and speech, work on speech processing has evolved into a separate

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