Lexical Semantic Students Presentations ICS 482 Natural

Lexical Semantic + Students Presentations ICS 482 Natural Language Processing Lecture 26: Lexical Semantic + Students Presentations Husni Al-Muhtaseb 3/18/2018 1

ﺑﺴﻢ ﺍﻟﻠﻪ ﺍﻟﺮﺣﻤﻦ ﺍﻟﺮﺣﻴﻢ ICS 482 Natural Language Processing Lecture 26: Lexical Semantic + Students Presentations Husni Al-Muhtaseb 3/18/2018 2

NLP Credits and Acknowledgment These slides were adapted from presentations of the Authors of the book SPEECH and LANGUAGE PROCESSING: An Introduction to Natural Language Processing, Computational Linguistics, and Speech Recognition and some modifications from presentations found in the WEB by several scholars including the following

NLP Credits and Acknowledgment If your name is missing please contact me muhtaseb At Kfupm. Edu. sa

NLP Credits and Acknowledgment Husni Al-Muhtaseb James Martin Jim Martin Dan Jurafsky Sandiway Fong Song young in Paula Matuszek Mary-Angela Papalaskari Dick Crouch Tracy Kin L. Venkata Subramaniam Martin Volk Bruce R. Maxim Jan Hajič Srinath Srinivasa Simeon Ntafos Paolo Pirjanian Ricardo Vilalta Tom Lenaerts Heshaam Feili Björn Gambäck Christian Korthals Thomas G. Dietterich Devika Subramanian Duminda Wijesekera Lee Mc. Cluskey David J. Kriegman Kathleen Mc. Keown Michael J. Ciaraldi David Finkel Min-Yen Kan Andreas Geyer. Schulz Franz J. Kurfess Tim Finin Nadjet Bouayad Khurshid Ahmad Staffan Larsson Robert Wilensky Feiyu Xu Jakub Piskorski Rohini Srihari Mark Sanderson Andrew Elks Marc Davis Ray Larson Jimmy Lin Marti Hearst Andrew Mc. Callum Nick Kushmerick Mark Craven Chia-Hui Chang Martha Palmer julia hirschberg Elaine Rich Christof Monz Bonnie J. Dorr Nizar Habash Massimo Poesio David Goss-Grubbs Thomas K Harris John Hutchins Alexandros Potamianos Mike Rosner Latifa Al-Sulaiti Giorgio Satta Jerry R. Hobbs Christopher Manning Hinrich Schütze Alexander Gelbukh Gina-Anne Levow Guitao Gao

Previous Lectures NLP Applications - Chatting with Alice o Introduction and Phases of an NLP system o Finite State Automata & Regular Expressions & languages o Morphology: Inflectional & Derivational o Parsing and Finite State Transducers, Porter Stemmer o Statistical NLP – Language Modeling o N Grams, Smoothing o Parts of Speech - Arabic Parts of Speech o Syntax: Context Free Grammar (CFG) & Parsing o Parsing: Earley’s Algorithm o Probabilistic Parsing o Probabilistic CYK (Cocke-Younger-Kasami) o Dependency Grammar o Invited Speech: Lexicons and Morphology o Semantics: Representing meaning o Semantics: First Order Predicate Calculus o Semantic Analysis: Syntactic-Driven Semantic Analysis Sunday, March 18, 2018 o Information Extraction o 6

Today's Lecture Lexical Semantics (Ch 16) o Students’ Presentations o Sunday, March 18, 2018 7

Students’ Presentations o Sunday May 20 (Today) n n n o Abbas Al-Julaih - An Ambiguity-Controlled Morphological Analyzer for Modern Standard Arabic Modeling Abdi. Rahman Daoud - Online Arabic Handwriting Recognition Using HMM (Did not attend) Shaker Al-Anazi - How Do Search Engines Handle Arabic Queries? Tuesday, May 22 (Next Time) n n n Hussain AL-Ibrahem - Arabic Tokenization, Part-of-Speech Tagging Ahmed Bukhamsin - Hybrid Method for Tagging Arabic Text Al-Ansari, Naser - Light Stemming for Arabic Information Retrieval Sunday, March 18, 2018 8

Lexical Semantics (Chapter 16) 3/18/2018 9

Spoken input For speech understanding Basic Process of NLU Phonological / morphological analyzer Sequence of words “He likes Ali. ” SYNTACTIC COMPONENT He likes Phonological & morphological rules Grammatical Knowledge Indicating relations between words Syntactic structure (parse tree) Ali SEMANTIC INTERPRETER x likes(x, Ali) Semantic rules, Lexical semantics Selectional restrictions Logical form CONTEXTUAL REASONER likes(Sami, Ali) Sunday, March 18, 2018 Thematic Roles Pragmatic & World Knowledge Meaning Representation 10

Words (Input) Parsing Words (Response) Lexicon and Grammar Syntactic Structure and Logical Form of Response Syntactic Structure and Logical Form Contextual Interpretation Realisation Discourse Context Utterance Planning Meaning of Response Final Meaning Application Context NLP Sunday, March 18, 2018 Application Reasoning 11

Meaning o Traditionally, meaning in language has been studied from three perspectives The meaning of a text or discourse n The meanings of individual sentences or utterances n The meanings of individual words n o We started in the middle, now we’ll move down to words and then we should move back up to discourse Sunday, March 18, 2018 12

Word Meaning o We didn’t assume much about the meaning of words when we talked about sentence meanings Verbs provided a template-like predicate argument structure n Nouns were practically meaningless constants n o There has be more to it than that Sunday, March 18, 2018 13

Preliminaries o What’s a word? n n n o Lexeme: an entry in the lexicon that includes n n n o Types, tokens, stems, roots, inflected forms, etc. . . Lexeme: An entry in a lexicon consisting of a pairing of a form with a single meaning representation Lexicon: A collection of lexemes an orthographic representation a phonological form a symbolic meaning representation or sense Dictionary entries: n n Red (‘red) n: the color of blood or a ruby Blood (‘bluhd) n: the red liquid that circulates in the heart, arteries and veins of animals Sunday, March 18, 2018 14

Relation Among Lexemes & Their Senses o Homonymy o Synonymy o Polysemy o Metonymy o Hyponymy/Hypernym o Meronymy o Antonymy Sunday, March 18, 2018 15

Relation Among Lexemes & Their Senses o Homonymy: n Lexemes that share a form o Phonological, orthographic or both n example: o Bat ( ﻣﻀﺮﺏ wooden stick-like thing) vs o Bat (ﻭﻃﻮﺍﻁ flying scary mammal thing) Sunday, March 18, 2018 16

Synonymy o o Different ways of expressing related concepts Examples n o o cat, feline, Siamese cat Overlaps with basic and subordinate levels Synonyms are almost never truly substitutable: n n Used in different contexts Have different implications o This is a point of debate Sunday, March 18, 2018 17

Polysemy o Most words have more than one sense n Homonym: same word, different meaning o bank (river) o bank (financial) n Polysemy: different senses of same word o That dog has floppy ears. o He has a good ear for jokes. o bank (financial) has several related senses n Sunday, March 18, 2018 the building, the institution, the notion of where money is stored 18

Metonymy o Use one aspect of something to stand for the whole Newscast: “The White House released new figures today. ” n Metaphor: Assuming the White house can release figures (like a person) n Sunday, March 18, 2018 19

Hyponymy/Hypernym o ISA relation o Related to Superordinate and Subordinate level categories hyponym(robin, bird) n hyponym(bird, animal) n hyponym(emus, bird) n o A is a hypernym of B is a type of A o A is a hyponym of B if A is a type of B Sunday, March 18, 2018 20

Basic-Level Categories o Folk biology: n {Unique beginner}: plant, animal o Life form: tree, bush, flower n o o Generic name: pine, oak, maple, elm o Specific name: Ponderosa pine, white pine - Varietals name: Western Ponderosa pine No overlap between levels Level 3 is basic n n Corresponds to genus Folk biological categories correspond accurately to scientific biological categories only at the basic level Sunday, March 18, 2018 21

Psychologically Primary Levels SUPERORDINATE animal furniture BASIC LEVEL dog chair SUBORDINATE terrier rocker o Children take longer to learn superordinate o Superordinate not associated with mental images or motor actions ! ﻛﻠﺐ ﺻﻴﺪ Sunday, March 18, 2018 ﻛﺮﺳﻲ ﻫﺰﺍﺯ 22

Meronymy o Parts-of relation part of(beak , bird) n part of(bark , tree) n ﻣﻨﻘﺎﺭ ﻟﺤﺎﺀ o Transitive conceptually but not lexically: The knob is a part of the door. n The door is a part of the house. n ? The knob is a part of the house ? n Sunday, March 18, 2018 23

Antonymy o Lexical opposites antonym(large, small) n antonym(big, little) n but not large, little n Sunday, March 18, 2018 24

Thesauri and Lexical Relations o Polysemy: Same word, different senses of meaning n Slightly different concepts expressed similarly o Synonyms: Different words, related senses of meanings n Different ways to express similar concepts o Thesauri help draw all these together o Thesauri also commonly define a set of relations between terms that is similar to lexical relations Sunday, March 18, 2018 25

What is an Ontology? o From Merriam-Webster’s Collegiate: n n o Or: n n o A carving up of the world’s meanings Determine what things exist, but not how they inter-relate Related terms: n o A branch of metaphysics concerned with the nature and relations of being A particular theory about the nature of being or the kinds of existence Taxonomy, dictionary, category structure Commonly used now in CS literature to describe structures that function as Thesauri Sunday, March 18, 2018 26

Example of Ontology Sunday, March 18, 2018 27

http: //www. cogsci. princeton. edu/~wn/5 papers. pdf Sunday, March 18, 2018 28

http: //www. cogsci. princeton. edu/~wn/5 papers. pdf Sunday, March 18, 2018 29

Resources o There are lots of lexical resources available these days… Word lists n On-line dictionaries n Corpora n o The most ambitious one is Word. Net n A database of lexical relations for English o Versions for other languages are under development Sunday, March 18, 2018 30

Word. Net o The critical thing to grasp about Word. Net is the notion of a synset; its their version of a sense or a concept n n o Example: table as a verb to mean defer n o Synset: set of synonyms, a dictionary-style definition (or gloss), and some examples of uses --> a concept Databases for nouns, verbs, and modifiers > {postpone, hold over, table, shelve, set back, defer, remit, put off} For Word. Net, the meaning of this sense of table is this list. Sunday, March 18, 2018 31

Word. Net 2. 1 newer than the one in the book POS Unique Synsets Strings Noun 117097 81426 Verb 11488 13650 Adjective 22141 18877 Adverb 4601 3644 Totals 155327 117597 Sunday, March 18, 2018 Total Word-Sense Pairs 145104 24890 31302 5720 207016 32

Lexical Relations in Word. Net Sunday, March 18, 2018 33

Structure of Word. Net Sunday, March 18, 2018 34

Structure of Word. Net Sunday, March 18, 2018 35

Structure of Word. Net Sunday, March 18, 2018 36

Word. Net Usage o Available online if you wish to try it… http: //wordnet. princeton. edu/ Sunday, March 18, 2018 37

Arabic Word. Net ? Sunday, March 18, 2018 38

Reminder: Choose your project o o o o Arabic POS Tagger Specific Information Picker An Arabic morphological analyzer An Arabic Spell checker w/ morphology analysis An Arabic Syntax analyzer Random syntactically-correct Arabic sentence generator An English to Arabic machine translation using word re-ordering Your Own: Let us discuss Sunday, March 18, 2018 39

Thank you ﺍﻟﺴﻼﻡ ﻋﻠﻴﻜﻢ ﻭﺭﺣﻤﺔ ﺍﻟﻠﻪ o Sunday, March 18, 2018 40