semLecture8

Albert Gatt
LIN 1180 – SemanticsLecture 8
Hyponymy and other relations
Part 1
Definition of hyponymy
LIN 1180 -- Semantics
Hyponymy is arelation of inclusion.Arrows can be interpreted as “IS-A” relations.Unlike taxonomic sisterhood, which is horizontal, hyponymy is vertical.
ANIMAL
MAMMAL
BIRD
CANARY
SPARROW
Elements of hyponymy
LIN 1180 -- Semantics
IfY IS-A Xthen:X is thesuperordinateorhypernymof YY is asubordinateorhyponymof Xe.g. HUMAN is the hypernym of MAN, TOOL is the hypernym of CHAINSAWInclusion: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
Transitivity -- illustration
LIN 1180 -- Semantics
A CANARY IS-A BIRDA BIRD IS-A ANIMALTherefore, a CANARY IS-A ANIMAL
ANIMAL
BIRD
SPARROW
CANARY
MAMMAL
Hierarchical representations and inheritance
Semantics -- LIN 1180
A node in a conceptual networkinheritssome properties from its superordinateIt can also add new properties of its ownIt canoverrideproperties of the superordinate
ANIMAL
BIRD
MovesEatsbreathes
FliesHas feathers
OSTRICH
Does not fly
Levels of conceptual representation
Semantics -- LIN 1180
Rosch et al. 1976 propose 3 levels
FURNITURE
CHAIR
ARMCHAIR
TABLE
SuperordinateOr “top” level
Basic level:This is the level we tendto use and think about
Subordinate level:Much more specific
Properties of the basic level
Semantics -- LIN 1180
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 simpleCompare:spoonvs.teaspoon, soup spoon…
More properties of the basic level
Semantics -- LIN 1180
high distinctivenessmaximally different from other categoriesstrong within-category resemblanceobjects within the category resembleeachothermore than they do objects outside the categoryoptimal level ofinformativeness: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…
Special cases of taxonomic relations
LIN 1180 -- Semantics
Sometimes, language exhibits special cases of relations that are:well-established and lexicalisedseem to depend on an underlying taxonomy or hierarchyADULT-YOUNGdog – puppy, duck – duckling, etcMALE-FEMALEwoman – man, dog – bitch, drake – duck, etcNB: These pairs are oftenasymmetric. The unmarked case in the MALE-FEMALE is the MALE.We tend to use it for the name of the species.
Meronymy or part-whole
LIN 1180 -- Semantics
A different kind of taxonomic relationship. Arrows are interpreted as “HAS-A”
ANIMAL
BIRD
WING
LEG
HAS-A
IS-A
HAS-A
Meronymy vs. Hyponymy
LIN 1180 -- Semantics
Meronymy tends to be less regular than hyponymy:NOSE is perceived as a necessary part of a FACECELLAR may be part of HOUSE, but not necessarilyMeronymyneed not be transitive:If X HAS-A Y and Y HAS-A Z, it does not follow that Y HAS-A Zwindow HAS-A paneroom HAS-A window??room HAS-A paneCommon-senseknowledge plays a very important role in acceptability of these relations.
Member-collection relations
LIN 1180 -- Semantics
We often lexicalise names of collections of specific things:flotta (fleet) : a collection of shipsmerħla (flock): a collection of sheepNativespeakers know there is a member-collection relation:flotta (fleet) – vapur (ship)armata (army) – suldat (soldier)merħla (flock) – nagħġa (sheep)Canbe viewed as a special, lexicalised case of meronymy.
Are collections singular or plural?
LIN 1180 -- Semantics
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 setEnglish:The band played well tonight.It drove the crowd nuts[SG]They drove the crowd nuts[PL]Maltese:L-armatartirat(The army retreated.SG)?L-armatartiraw. (The army retreated.PL)Perhaps not as acceptable? Only with some nouns?
Beyond the lexicon: Overviewof sentence relations
Part 2
In this lecture
LIN 1180 - Semantics
Having looked in some detail at properties of the lexicon, we now turn to sentences.Wediscussmeaning relations between sentencestruth conditionspresupposition
Sentence relations
LIN 1180 - Semantics
Just as lexical items stand in various relations to one another (hyponymy, etc), so do sentences:Relationsbetween sentences arise due to:the lexical items in themtheir grammatical structure
Sentence synonymy
LIN 1180 - Semantics
My brother is a bachelorMy brother is an unmarried man(1) and (2) seem to have the samemeaning (or almost... Cf. Our discussion of synonymy)
Entailment
LIN 1180 - Semantics
My sister assassinated the president.The president is dead.(1) entails (2), primarily because of the meaning ofassassinate.if (1) is true, then (2) must be trueThe following arenotin an entailment relationship:My sistershotthe president.The president is dead.If (1) isnegated, it no longer entails (2):My sister did not assassinate the president.
Important properties of entailment
LIN 1180 - Semantics
A sentence p entails a sentence q if, and only if:q is true whenever p is trueq is false whenever p is falseThis is why entailment iscancelled by negation.
How does entailment arise?
LIN 1180 - Semantics
Lexical, e.g. hyponymyMy sister assassinated X X died.assassinateYincludesY diesI bought a dog I bought an animaldogis a hyponym ofanimalSyntactic, e.g. active/passiveMy sister assassinated the presidentThe president was assassinated by my sister.
Contradiction
LIN 1180 - Semantics
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
Tautology
LIN 1180 - Semantics
Albert is AlbertThis classroom is this classroom.Both (1) and (2) arenecessarily trueIn fact, both are highly uninformative sentences.