Page 223 - DCAP310_INTRODUCTION_TO_ARTIFICIAL_INTELLIGENCE_AND_EXPERT_SYSTEMS

Unit 12: Natural Language Processing

Notes

Notes Ambiguously, the word is sometimes also used to refer to a polyglot (one who
knows several languages), or a grammarian (a scholar of grammar), but these two uses of
the word are distinct (and one does not have to be a polyglot in order to be an academic
linguist).

12.1.1 Computational Linguistics

Computational linguistics is an interdisciplinary field dealing with the statistical or rule-based
modeling of natural language from a computational perspective.

Traditionally, computational linguistics was usually performed by computer scientists who had
specialized in the application of computers to the processing of a natural language. Computational
linguists often work as members of interdisciplinary teams, including linguists (specifically
trained in linguistics), language experts (persons with some level of ability in the languages
relevant to a given project), and computer scientists. In general, computational linguistics draws
upon the involvement of linguists, computer scientists, experts in artificial intelligence,
mathematicians, logicians, philosophers, cognitive scientists, cognitive psychologists,
psycholinguists, anthropologists and neuroscientists, among others.

Computational linguistics has theoretical and applied components, where theoretical
computational linguistics takes up issues in theoretical linguistics and cognitive science, and
applied computational linguistics focuses on the practical outcome of modelling human language
use. Computational linguistics (CL) is a discipline between linguistics and computer science
which is concerned with the computational aspects of the human language faculty. It belongs to
the cognitive sciences and overlaps with the field of artificial intelligence (AI), a branch of
computer science aiming at computational models of human cognition. Computational
linguistics has applied and theoretical components.

Self Assessment

State whether the following statements are true or false:
1. Linguistics is the study of human languages.

2. There are some branches of linguistics.
3. Linguists also attempt to describe how bigger units can be combined to form smaller
grammatical units.

12.2 Grammars and Languages

In formal language theory, a grammar (when the context isn’t given, often called a formal
grammar for clarity) is a set of production rules for strings in a formal language. The rules
describe how to form strings from the language’s alphabet that are valid according to the
language’s syntax. A grammar does not describe the meaning of the strings or what can be done
with them in whatever context—only their form.
Formal language theory, the discipline which studies formal grammars and languages, is a
branch of applied mathematics. Its applications are found in theoretical computer science,
theoretical linguistics, formal semantics, mathematical logic, and other areas.

LOVELY PROFESSIONAL UNIVERSITY 217