1. Introduction to Computational Linguistics
Lecture 1
Introduction to Computational Linguistics
Dr. Radhika Mamidi
ENG 270

2. What is Linguistics? The scientific study of human language
Aim is to establish a theory by studying nature of a language and by applying this established theory to describe other languages
Descriptive study not prescriptive
Speech activity - speaker, hearer, setting, code, medium; plus topic, contextual knowledge, abiding social norms, communicative competence

3. Applied Linguistics Subfields / Inter-disciplinary fields:
Sociolinguistics Lexicography
Stylistics Computational Linguistics
Semiotics Psycholinguistics
Language Teaching/Learning
Translation Studies
Anthropological Linguistics
Note: Now ‘Applied Linguistics’ is associated with Lg teaching.

4. What is Computational linguistics?
“Computational linguistics is an interdisciplinary field dealing with the statistical and logical modeling of natural language from a computational perspective.”

5. Goal of Computational linguistics
To make the computers understand human language.
To use technology to build language tools.
Use computers to process or produce human language.
We want to communicate with computers in the language we speak!

6. Why Computers should talk with us?
The main obstacle in the interaction between human and computer is communication problem.
Computers do not understand our language and learning computer language is difficult.
Computer language do not match the structure of human thought.
The use of human language in computer applications will benefit the user.

7. Most interesting CL application: chatbot
A chatterbot (or chatbot) is a type of conversational agent.
It is a computer program designed to simulate an intelligent conversation with one or more human users via auditory or textual methods.
It is a computer program with artificial intelligence to talk to people through voices or typed words.

9. Computational Linguistics
Computational linguistics is an interdisciplinary field. It takes input from different fields.
Linguistics
Mathematics
Cognitive Science
Computational Linguistics
Philosophy
Psychology
Computer Science

10. Relation of CL to Other Disciplines
Artificial Intelligence (notions of representation, search)
Machine Learning (probabilistic or statistical techniques)
Human Computer Interaction (HCI)
Linguistics (Syntax, Semantics etc.)
Information Retrieval
Philosophy of language (formal logic)
Electrical Engineering (Optical Character Recognition)
Psychology (insight into learning of linguistic constructions)

11. Computational Linguistics is closely related to…
Natural Language Technology
Natural Language Engineering
Natural Language Processing
Artificial Intelligence

12. Some Applications of Computational Linguistics
Spelling and Grammar Checkers
Screen readers for the blind
Machine readable Dictionaries
Machine Translation Systems
Question-Answering Systems
Information Retrieval
Information Extraction
Automatic Summarization

13. Example Application- Search Engine

14. Example Application- Spelling Checker

15. Example Application- Grammar Checker

16. Example Application- Question Answering

17. Example Application- Machine Translation

18. Careers for Computational linguists
Academia
Research and Higher education
Teaching in IT or English
Industry
Companies that work in fields like:
speech technology, information extraction, machine translation, automatic summarization, etc.
Microsoft, Google, HP Labs, Xerox Research are some major companies developing language tools.
Information Technology departments of Banks
Web designing that needs language and computer knowledge

19. Likely jobs for Computational linguists
Software Engineers
Researchers in Machine Translation
Teachers of Computer Science/Linguistics in schools
Linguistic database analyzers
Designers of mono/bi-lingual dictionaries
Speech technologists
Teaching or Research Assistants

20. Getting a job in language technology
Best candidate has:
Advanced degree in linguistics
Coursework or major in computational linguistics or computer science
Knowledge of foreign language(s)
Computer scripting or programming skills
Work or internship in industry

21. Some companies that hire computational linguists
CL Research - tools for developing lexical databases
Comverse - speech technology for computers and internet
Cycorp
IBM - dictation software for English and other languages
Language Intelligence - a linguistic software company
Lingsoft - a linguistic software company
Scansoft - speech recognition systems
Soliloquy - natural language understanding software
Microsoft - software for dictation and text-to-speech

22. Exercise 1
Write down what you have understood by ‘Computational Linguistics’?
Try the different applications mentioned and write down your observations.
Do you think the tools are useful to us?
Submit your work before the next class.

23. Exercise 2
Observe how the spelling and grammar checker on your pc works. Give 5 errors that were pointed out by each tool.
Practice giving the right keywords to search for a document using Google or Yahoo. Give the results.
Look for different chatbots, make a list of the urls, talk to them and judge which one is the best one.
To Do
Write down your observations and submit them as soon as you are done.

24. Assignment 1 Due date: After 2 weeks
Write short essays [minimum 8-10 sentences] on the following topics:
Spelling and grammar checkers
Your favorite search engine
You and a chatbot
You have to include examples, urls, references, sample data etc. wherever necessary.
Marks will be deducted if any kind of plagiarism is found.