Natural Language Processing - Chapter 1: Introduction and Overview of NLP

N.L.P. NATURAL LANGUAGE PROCESSING  Teacher: Lê Ngọc Tấn  Email: letan.dhcn@gmail.com  Blog: Trường Đại học Công nghiệp Tp. HCM Khoa Công nghệ thông tin (Faculty of Information Technology) NLP. p.2 CONTENT  Chapter 1. Introduction and Overview of NLP  Chapter 2. Fundamental algorithms and mathematical models  Chapter 3. Basic principles for NLP  Chapter 4. Computational Linguistics  Chapter 5. Foundation of Statistical Machine Translation C.1 – Introduction and Overview of NLP NLP. p.3 Chapter 1 Introduction and Overview of NLP C.1 – Introduction and Overview of NLP  Introduce some of the classical problems in NLP  Learn to address empirical problems – Is one system for a task better than another – Understand where and how a system fails – Propose possible solutions  Talk/write clearly about your work, decision and observations NLP. p.4 In NLP module, we will C.1 – Introduction and Overview of NLP  No background in NLP is required  Expect to know a bit of basic probability (know Bayes rules)  Know a bit about vectors and vector space, a bit of calculus (matrices)  Have reasonable programming ability (know about hash tables and graph data structures, Java, Python, Perl, Prolog,) NLP. p.5 What background do I need? C.1 – Introduction and Overview of NLP Why is natural language understanding difficult?  Non-standard English  Segmentation issues  Neologisms  World knowledge  Idioms  Tricky entity names NLP. p.6C.1 – Introduction and Overview of NLP Can machines understand language ?  Which aspects of language are easy for people but difficult for machines? – Syntactic and semantic ambiguities Ex: I ate cherry pie with ice cream. I ate cherry pie with a spoon. The astronomer married the star. (semantic) NLP. p.7C.1 – Introduction and Overview of NLP What is the NLP ?  NLP stands for Natural Language Processing  Definition: It is the study of linguistics concerned with the interactions between computers and human natural languages  NLP is a field of computer science, artificial intelligence and linguistics. NLP. p.8C.1 – Introduction and Overview of NLP NLP applications 1. Spelling and grammar correction in word process 2. Human translators on the Web 3. Information retrieval 4. Information extraction 5. Automatic question answering 6. Detecting people’s opinions about products or services 7. Text Summarization 8. Linguistics Learning assisted by computer 9. NLP. p.9C.1 – Introduction and Overview of NLP Programming languages in NLP  Script languages such as Python, Perl, Prolog,  Java  C/C++/C# NLP. p.10C.1 – Introduction and Overview of NLP What tools do we need?  Knowledge about language  Knowledge about the world  A way to combine knowledge sources  How we generally do this: – Probabilistic models built from language data Ex: P(“nhà”  “house”) high P(“đường”  “sugar”) low – Luckily, rough text features can often do half the job NLP. p.11C.1 – Introduction and Overview of NLP The hottest issues in NLP  Word segmentation, WSD – Word Sense Disambiguation, Word Reordering,  POS tagging  Syntactic parsing  Semantic analysis  Statistical Machine Translation NLP. p.12C.1 – Introduction and Overview of NLP