LIN 1180 – Semantics Lecture 8

Slides:



Advertisements
Similar presentations
Page 1 E N T A I L M E N T By: Riza Nirmala Putri.
Advertisements

Albert Gatt LIN 1180 – Semantics Lecture7. Ambiguity and vagueness Continuation from last week.
Semantics Unit 5 - Predicates Part 2
Topic 5: sense Introduction to Semantics. Definition The sense of an expression is its indispensable hard core of meaning. The sum of sense properties.
SEMANTICS.
Unit 10-Part 2 Practice 6-15.
Semantics Chapter 5.
Modality Lecture 10. Language is not merely used for conveying factual information A speaker may wish to indicate a degree of certainty to try to influence.
Cognitive Linguistics Croft & Cruse 6 A dynamic construal approach to sense relations I: hyponymy and meronymy.
Statistical NLP: Lecture 3
Chapter 7 Knowledge Terms: concept, categorization, prototype, typicality effect, object concepts, rule-governed, exemplars, hierarchical organization,
INTRODUCTION TO ARTIFICIAL INTELLIGENCE Massimo Poesio LECTURE 4: Semantic Networks and Description Logics.
Cognitive Linguistics Croft&Cruse 4: Categories,concepts, and meanings, pt. 1.
Nouns and Countability. Outline Introduction Conceptual Semantics Chierchia’s approach Natural Semantic Metalanguage Conclusion.
Albert Gatt LIN1180 – Semantics Lecture 10. Part 1 (from last week) Theories of presupposition: the semantics- pragmatics interface.
 Contrary to the beliefs of early workers in AI, experience has shown that Intelligent Systems cannot achieve anything useful unless they contain a large.
Linguistic Theory Lecture 8 Meaning and Grammar. A brief history In classical and traditional grammar not much distinction was made between grammar and.
Knowledge ß How do we organize our knowledge? ß How do we access our knowledge? ß Do we really use categories?
Concepts and Categories. Functions of Concepts By dividing the world into classes of things to decrease the amount of information we need to learn, perceive,
Natural Categories Hierarchical organization of categories –Superordinate (e.g., furniture) –Basic-level (e.g., chair) –Subordinate (e.g., armchair) Rosch.
1/27 Semantics Going beyond syntax. 2/27 Semantics Relationship between surface form and meaning What is meaning? Lexical semantics Syntax and semantics.
From Semantic Similarity to Semantic Relations Georgeta Bordea, November 25 Based on a talk by Alessandro Lenci titled “Will DS ever become Semantic?”,
Meaning and Language Part 1.
The Study of Meaning in Language
LEXICAL RELATION (2) TRUTH CONDITIONAL SEMANTICS:
LIN1180/LIN5082 Semantics Lecture 3
Semantics.
Unit Five Semantics, Study of Meaning
Albert Gatt LIN1180 Semantics. In this lecture More on the concept of truth A priori / necessary / analytic Presupposition.
Meaning. Semantics (the study of meaning) Semantics: the study of meaning, or to be more specific, the study of the meaning of linguistic units, words.
Ch. 5 The Internal Lexicon
PSY 323 – COGNITION Chapter 9: Knowledge.  Categorization ◦ Process by which things are placed into groups  Concept ◦ Mental groupings of similar objects,
Semantics The study of meaning in language. Semantics is…  The study of meaning in language.  It deals with the meaning of words (Lexical semantics)
Semantics Continued… Meaning Relationships Entailments Maxims of Conversation.
Semantic/ meaning Fields and Components of Meaning.
Category Structure Psychology 355: Cognitive Psychology Instructor: John Miyamoto 05/20 /2015: Lecture 08-2 This Powerpoint presentation may contain macros.
LEXICAL RELATIONS Presented by ‘the big family’ group 3 Rauwan Harahap (Opung) Riza Nirmala Putri Salmah Silih Warni Siti Anifah Siti Juariyah.
LECTURE 2: SEMANTICS IN LINGUISTICS
Sense of Properties and Stereotypes
What is a concept? Part of semantic memory (vs. episodic memory) A class of items that seem to belong together –‘dog’, ‘balloon’, ‘terrorist’ (things)
Wordnet - A lexical database for the English Language.
SEMANTICS An Introduction to Linguistics. What does semantics study? Semantics studies the meaning of language.
Long Term Memory: Semantic Kimberley Clow
1 How is knowledge stored? Human knowledge comes in 2 varieties: Concepts Concepts Relations among concepts Relations among concepts So any theory of how.
LEXICAL INTERFACE 2 OCT 26, 2015 – DAY 25 Brain & Language LING NSCI Fall 2015.
1 (Introduction to Word Grammar) Richard Hudson Joensuu November 2010 Words are concepts.
Lecture 8 – Categories 1 great detail is needed for planning & executing current responses some detail about context of new learning can be emcoded with.
Semantics Nuha Alwadaani. Semantics Semantics is the study of the meaning of words, phrases and sentences. Conceptual meaning: covers those basic, essential.
The “Gavagai” problem How do we learn new words? What is the speaker naming?
Semantics Lecture 5. Semantics Language uses a system of linguistic signs, each of which is a combination of meaning and phonological and/or orthographic.
SEMANTICS Chapter 10 Ms. Abrar Mujaddidi. What is semantics?  Semantics is the study of the conventional meaning conveyed by the use of words, phrases.
Chapter 7 Semantics. Semantics: the study of meaning in language lexical semantics: the study of how words mean sentence semantics: What is ‘studying.
Chapter 3 Word Meaning.
King Faisal University جامعة الملك فيصل Deanship of E-Learning and Distance Education عمادة التعلم الإلكتروني والتعليم عن بعد [ ] 1 King Faisal University.
Module 5 Other Knowledge Representation Formalisms
Week 3b. Merge, feature checking
Entailment Sentence meaning vs. pragmatic meaning
Statistical NLP: Lecture 3
LEXICAL RELATIONS IN DISCOURSE
Language, Logic, and Meaning
What is Linguistics? The scientific study of human language
The Ontological Argument
An Introduction to Linguistics
Introduction to Linguistics
The Ontological Argument
The Study of Meaning in Language
Lexis and Semantics Revision
The Classical Approach to Categorization
Categories My dog sleeping. My dog. All golden retrievers. All dogs. All canines. All mammals… Each of these is a category. Categorization is the process.
Intension and Extension
Presentation transcript:

LIN 1180 – Semantics Lecture 8 Albert Gatt

Hyponymy and other relations Part 1 Hyponymy and other relations

Definition of hyponymy Hyponymy is a relation of inclusion. Arrows can be interpreted as “IS-A” relations. Unlike taxonomic sisterhood, which is horizontal, hyponymy is vertical. ANIMAL BIRD MAMMAL CANARY SPARROW LIN 1180 -- Semantics

Elements of hyponymy If Y IS-A X then: Inclusion: Transitivity: X is the superordinate or hypernym of Y Y is a subordinate or hyponym of X e.g. HUMAN is the hypernym of MAN, TOOL is the hypernym of CHAINSAW Inclusion: if Y is a hyponym of X then Y contains the meaning of X (plus something extra) e.g. MAN includes all the features of HUMAN, plus the specification of ADULT and MALE. Transitivity: if X IS-A Y and Y IS-A Z, then X IS-A Z LIN 1180 -- Semantics

Transitivity -- illustration A CANARY IS-A BIRD A BIRD IS-A ANIMAL Therefore, a CANARY IS-A ANIMAL ANIMAL BIRD MAMMAL CANARY SPARROW LIN 1180 -- Semantics

Hierarchical representations and inheritance A node in a conceptual network inherits some properties from its superordinate It can also add new properties of its own It can override properties of the superordinate Moves Eats breathes ANIMAL BIRD Flies Has feathers Does not fly OSTRICH Semantics -- LIN 1180

Levels of conceptual representation Rosch et al. 1976 propose 3 levels Superordinate Or “top” level FURNITURE Basic level: This is the level we tend to use and think about CHAIR TABLE Subordinate level: Much more specific ARMCHAIR Semantics -- LIN 1180

Properties of the basic level The easiest to visualise: easier to imagine a CAR (basic) than a FIAT PUNTO (subordinate) Used for neutral, everyday usage: we’re more likely to say “that’s a dog” than “that’s a dachshund” or “that’s an animal” Names of basic-level categories tend to be morphologically simple Compare: spoon vs. teaspoon, soup spoon… Semantics -- LIN 1180

More properties of the basic level high distinctiveness maximally different from other categories strong within-category resemblance objects within the category resemble eachother more than they do objects outside the category optimal level of informativeness: it’s more informative to say “x is a dog” than “x is an animal” but in most cases, saying “x is a dachshund” is too specific… Semantics -- LIN 1180

Special cases of taxonomic relations Sometimes, language exhibits special cases of relations that are: well-established and lexicalised seem to depend on an underlying taxonomy or hierarchy ADULT-YOUNG dog – puppy, duck – duckling, etc MALE-FEMALE woman – man, dog – bitch, drake – duck, etc NB: These pairs are often asymmetric. The unmarked case in the MALE- FEMALE is the MALE. We tend to use it for the name of the species. LIN 1180 -- Semantics

Meronymy or part-whole A different kind of taxonomic relationship. Arrows are interpreted as “HAS-A” LEG ANIMAL HAS-A IS-A WING BIRD HAS-A LIN 1180 -- Semantics

Meronymy vs. Hyponymy Meronymy tends to be less regular than hyponymy: NOSE is perceived as a necessary part of a FACE CELLAR may be part of HOUSE, but not necessarily Meronymy need not be transitive: If X HAS-A Y and Y HAS-A Z, it does not follow that Y HAS-A Z window HAS-A pane room HAS-A window ??room HAS-A pane Common-sense knowledge plays a very important role in acceptability of these relations. LIN 1180 -- Semantics

Member-collection relations We often lexicalise names of collections of specific things: flotta (fleet) : a collection of ships merħla (flock): a collection of sheep Native speakers know there is a member-collection relation: flotta (fleet) – vapur (ship) armata (army) – suldat (soldier) merħla (flock) – nagħġa (sheep) Can be viewed as a special, lexicalised case of meronymy. LIN 1180 -- Semantics

Are collections singular or plural? In many languages, there is the possibility of switching from: a view of a collection as a single entity vs. the “contents” of the collection as a group or set English: The band played well tonight. It drove the crowd nuts [SG] They drove the crowd nuts [PL] Maltese: L-armata rtirat (The army retreated.SG) ?L-armata rtiraw. (The army retreated.PL) Perhaps not as acceptable? Only with some nouns? LIN 1180 -- Semantics

Beyond the lexicon: Overview of sentence relations Part 2 Beyond the lexicon: Overview of sentence relations

In this lecture Having looked in some detail at properties of the lexicon, we now turn to sentences. We discuss meaning relations between sentences truth conditions presupposition LIN 1180 - Semantics

Sentence relations Just as lexical items stand in various relations to one another (hyponymy, etc), so do sentences: Relations between sentences arise due to: the lexical items in them their grammatical structure LIN 1180 - Semantics

Sentence synonymy My brother is a bachelor My brother is an unmarried man (1) and (2) seem to have the same meaning (or almost... Cf. Our discussion of synonymy) LIN 1180 - Semantics

Entailment My sister assassinated the president. The president is dead. (1) entails (2), primarily because of the meaning of assassinate. if (1) is true, then (2) must be true The following are not in an entailment relationship: My sister shot the president. If (1) is negated, it no longer entails (2): My sister did not assassinate the president. LIN 1180 - Semantics

Important properties of entailment A sentence p entails a sentence q if, and only if: q is true whenever p is true q is false whenever p is false This is why entailment is cancelled by negation. LIN 1180 - Semantics

How does entailment arise? Lexical, e.g. hyponymy My sister assassinated X  X died. assassinate Y includes Y dies I bought a dog  I bought an animal dog is a hyponym of animal Syntactic, e.g. active/passive My sister assassinated the president  The president was assassinated by my sister. LIN 1180 - Semantics

Contradiction My canary has just escaped from its cage. My canary has never been in a cage. If (1) is true, then (2) cannot be true (and vice versa) (2) contradicts (1) He is a murderer but he’s never killed anyone. (3) is also a contradiction LIN 1180 - Semantics

Tautology Albert is Albert This classroom is this classroom. Both (1) and (2) are necessarily true In fact, both are highly uninformative sentences. LIN 1180 - Semantics