Notes
Slide Show
Outline
1
Semantics
  • (An overview)
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Outline
  • Basic principles
  • Denotation, meaning and reference
  • Semantic categories
  • Levels of description
  • Semantic phenomena
  • Semantic theories
  • The syntax/semantics interface
  • Computational semantics
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Basic principles
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Premises
  • Mind is innately structured, modular: subparts, particular functions, domains
  • Language module exists
  • Lang acq is central puzzle (learnability, innateness, universal grammar)
  • Semantics is a formal system (isolatable, describable, autonomous)
  • Knowledge of language is modular (phonology, morphology, syntax, semantics)
  • Crosslinguistic semantic regularities exist
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Intuitions
  • Competence (grammaticality, universal properties of language, data)
  • Ungrammaticality: “this can’t be a sentence”
  • Anomaly: “this sentence doesn’t make sense”
    • Colorless green ideas sleep furiously.
  • Categories: classes of words that behave similarly
    • POS (tags), function/content wrds
  • Constituents: word sequences that belong together
    • phrases, clauses, sentences
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Semantics
  • What components of linguistic processing contribute to meaning?
  • Characterization of the meaning of (parts of) utterances (word/phrase/clause/sen-tence)
  • To what extent can the meaning be derived (compositionally)? ambiguous?
  • Formalisms: networks, models, scripts, schemas, logic(s)
  • Non-literal use of language (metaphors, exaggeration, irony, etc.)
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Caveats
  • Not everybody agrees on the facts
  • Accounts are often heterogeneous
  • Other related areas are often excluded
    • Prosody
    • Pragmatics
    • Culture
    • Historical aspects of language change
  • Widely divergent approaches, theories exist


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Denotation, meaning and reference
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Approaches to meaning
  • Referential (denotational)
    • Relating symbols to external objects
    • Logic, mathematics, models
  • Psychological (mentalist)
    • Relating symbols to internal objects
    • AI, psycholinguistics, semantic representation
  • Pragmatic (social)
    • Communication as a social activity
    • Interactions, agency, conventions
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Denotation
  • Meaning via reference
  • Configure symbols: characterize relationships between objects
  • Linguistic reference
    • Proper nouns: individuals
    • NP’s
      • Individuals (or groups/collections thereof)
      • Substances, actions, abstract entities
  • But: nonreferentiality
    • A/some/every/no student sneezed.
    • The man who can lift this stone is stronger than an ox.
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Sense and reference
  • Expressions have both:
    • a reference: what it means on a given occasion (retinal image, subjective)
    • a sense: ways in which the reference is presented (lens image, objective)
  • Reference: actual real-world objects, individuals, classes (extension)
    • U.S. President: {Washington, Clinton, Bush, …}
  • Sense: inherent meaning, concepts, thoughts (intension)
    • U.S. President: elected leader of the U.S.
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Referential indices
  • Johni saw himj.
  • Johni saw himselfi.
  • Johni saw him*i/j.


  • Johni’s fatherj saw himi.


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More coreference
  • *Behind [Mary]i [she]i heard the snake.
  • *[Herself]i is proud of [her]i.
  • *If [that jerk]i calls, tell [Tom]i I’m busy tonight.
  • *[He]i insists that [the electrician]i found nothing wrong.
  • [Mary]i told [John]j that [they]/j/i/k were assigned clean-up duty.
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Referent resolution
  • Syntactic coreference principles (Binding Principles A-C, morphological features, distance)
  • Other methods
    • The Hobbs algorithm: ordering of syntactically-derived potential antecedents from previous utterances
    • The centering algorithm: cache of 2-3 previous sentences, stack-based memory, preference weighting among possible antecedents
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Basic meaning categories
  • Truth value
    • (adequacy?)
  • Concepts: basic entities
    • Inventories
  • Properties: attributes predicated of concepts
    • Intensity
    • Incommensurability
  • Events: actions, states, processes
    • Internal structure
  • Propositions: predicated assertions
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Meaning and literality
  • Literal meaning
    • Representation of states of affairs in the world
    • Decontextualized as much as possible
    • Objective, focused, structured
    • The approach we will strive to follow
  • Implicational meaning
    • What the speaker intended or what the hearer’s expected response is
    • Context is crucial to interpretation
    • Negotiable, subjective, variable
    • Not what our focus will be on
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Other aspects of meaning
  • Expressive meaning
    • Connotation, emotion, feelings
  • Prototypes
    • Most popularly evoked exemplars of a given concept
  • Stereotypes
    • Over-used (often incorrect) exemplars of a given concept
  • Evoked meaning
    • Dialects (geographical, temporal, social)
    • Register (discourse field, tenor, mode)
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Emotive/evaluative meaning
  • I am firm.
    You are obstinate.
    He is a pig-headed fool.
  • Fairer sex, female, broad
  • Between jobs, out of work, on the dole
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Idioms
  • Non-compositional collocations
  • Severe lexical constraints
    • Off his rocker/*rocking chair
    • Gnashing of teeth/*molars
    • Shot herself in the foot/*toe
  • Vary crosslinguistically


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Semantic categories
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Entities
  • What nouns traditionally refer to
  • Enumerability, discreteness, identifiability
  • Fundamental properties:
    • Specificity
    • Boundedness
    • Animacy
    • Sex and gender
    • Kinship
    • Social status
    • Physical properties
    • Function
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Entities: specificity
  • Uniqueness, degree of individuation, relative singularity
  • Ambiguity
    • I eat a hamburger every day.
      (specific, non-specific, generic readings)
    • Related effects: mood (Spn, Frn, etc.)
  • Implies the referent can be uniquely determined
  • Interactions
    • Given/new status in discourse
    • Knownàreferentially accessibleàspecificà definite
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Entities: boundedness
  • Count vs. mass
    • Enumerability vs. amorphousness
  • Boundedness
    • Is inherent, not derived from the context
    • Properties of internal structure:
      • Bounded: heterogeneous, unexpandable, replicable
      • Unbounded: not
  • Ambiguities
    • The gas escaped. (un-/bounded)
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Entities: other properties
  • Animacy: basic biological definition
    • In some languages other criteria sometimes apply: topicality, salience, culture, discourse
  • Person: information about participating relevant parties
    • 1st: self, selves (I, we)
    • 2nd: you (thou, you, y’all, yunz)
    • 3rd: others (he, she, it, they, them)
    • Further distinctions:
      • Singular/plural
      • Inclusive/ exclusive distinction
      • Distal (distance-based) distinction
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Entities: other properties
  • Case: marking an entity’s role in a sentence
    • Nominative=subject, Accusative=direct object, Dative=indirect object, Genitive=possession, Instrumental=means, method, Locative=location
    • (Russian: stol/stola/stolu/stol/stolom/stolje)
    • Varies crosslinguistically (mostly gone in English)
  • Physical properties
    • Interioricity (solids/outlines), size (large/small)
    • Extendedness
      • Dimensionality/shape
      • Direction, extension: vertical, horizontal
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Entities: other properties
  • Social status
    • Social relations between entities
    • Functions in various processes
    • Here: focus on morphosyntactic honorifics
  • Gender: grammatical category (formal)
    • Sex: inherent biological class (semantic)
  • Pronominalization
    • Subject/object, impersonal/personal, reflexive/reciprocal, etc.
    • Functional role: (co)reference, anaphoric, etc.


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Entities: classifiers
  • Semantic particles used when counting N’s
    • -bai (time), -bun (part), -chaku (clothing), -choo (beancurd), -dai (vehicle), -fuku (puff, cup), -hai (cup), -hatsu (ammunition round), -hen (volume, chapter, …), -hiki (small animal), -hon (cylindrical object), -ma (room), -shu (poem), -wa (bird), -zen (bowl of rice)
  • Usually based on salient properties of the item counted
  • Wide variation crosslinguistically
  • English has “collective nouns”
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Kinship relations
  • Fundamentally relational
  • Related properties: gender, age
  • Parameters
    • Consanguineal / affinal
    • Lineal / collateral
    • Generation
      • Directionality
      • Removal
  • Ambiguity
    • My grandfather visited me.
      (matrilineal, patrilineal)
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Events
  • Relatively temporal relation in conceptual space
  • States/conditions of existence, processes, unfoldings
  • Actions, executed processes inherently tied to change
  • Process: series of states constituting a phenomenon
  • Relationality: change is essential to identifying events
  • Temporality: time is a crucial element
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Acts vs. States
  • Stative events
    • Internally uniform
    • Scope: event as a totality
    • More stable temporally, no internal dynamics
    • Less sensitive to temporal distinctions
  • Nonstatives (acts)
    • Heterogeneous, internally structured
    • Scope: components
    • Substates involve more temporal change, dynamism
    • Usually nonpresent tenses
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Events: resultatives
  • Inchoatives
    • Denote interval between two intervals
    • Boundary crossing into a new condition
    • Can’t distribute to moments
  • Resultatives
    • Complex event: act + change-of-state
    • Not interruptible
    • Don’t saturate down to the moment
  • Ambiguities
    • This shrimp digests easily.
      (inchoative middle, resultative active)
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Events: voice
  • Active
    • Logical agent realized as structural subject
  • Passive
    • Logical agent realized obliquely
  • Middle
    • Structural subject of intransitive is the logical object
    • Constraint(s):
      • How affected the subject is: anomaly when affectedness is low
      • Component of becoming: action must be incohative
  • Ambiguity: The door was opened.
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Events: tense
  • Information dealing with temporal (time) properties
    • Past, future, present
      • manger+ai (Frn); sing+s
    • Remoteness is specified in some languages
    • Not just verbs in some languages
      • tu+pus (Lus)


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Events: causation
  • Subclass of acts; verbal=causatives
  • Relation of determination between 2 events
  • A language universal; usually verbal
  • Conveyance (e.g. vehicular: drove, trucked)
  • Manner
    • knocked, pounded, hammered (intensity, speed, …)
  • Cause
    • Often inherently encoded
      kill à cause + become + dead
      roll
      à cause + displacement + circular
    • Very periphrastic in other languages
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Events: transitivity
  • Information dealing with how much the verb transfers the action, and to whom
    • Transitive: action is transferred
    • Intransitive: action isn’t transferred
    • Ditransitive: direct and indirect object
    • Causative: some entity is made/caused to do something
  • Some verbs alternate
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Space and location
  • Space is relational:  dependency between 2 entities/events
    • Located object, reference object
  • Relations can be formalized
  • Location: spatial fixedness
    • Topological: viewer-independent (coincidence, interiority/exteriority)
    • Projective: viewer-dependent (infer-/super-iority, anter-/posteriority, laterality)
  • Ambiguities
    • My book is on the table.
      (non-/coincedent contact)
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Aspect
  • Definition(s)
    • Nontemporal internal contour of an event
    • How an event is distributed through a time frame
    • Patterns within an event’s temporal frame
  • English usually conflates with tense
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Aspectual types
  • Perfectivity
    • Perfective: complete, unitized, viewable as single bounded whole, internal structure less salient
    • Imperfective: opposite
    • Present tense: rarely perfective
    • Slavic languages: verb form dichotomy for imperfective/perfective
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Aspectual types
  • Telicity
    • Resultative: dual structure (process+result)
    • Success predicated on built-in goals
    • Necessarily imply previous events
    • Processes that exhaust themselves in their consequences
  • Durativity
    • Durative: necessarily distributed over time
    • Punctual: momentary event having no temporal duration


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Aspectual types
  • Progressivity
    • In progress, on-line, ongoing
    • Continuous and extended from a point into a larger interval
    • Extending an event from the inside
    • Interactions
      • w/punctual event: iterative
      • Simultaneity, coextensiveness
      • Stativizing dynamic events
      • Non-permanence, contingency
    • Wide linguistic variation
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Aspectual types
  • Habituality
    • Extends an event from the outside
    • Persistence of an event irrespective of time
    • Indefinite protraction of an event
    • Distribution of an event over several times
    • Not just a case of iteration
    • Interactions: perfectivity, past tense, conditional
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Aspectual types
  • Iterativity
    • Semelfactive: one act, event
    • Iterative: multiple subevents
    • Event cardinality, cyclicity, dual laterality
  • Other aspects
    • Inceptive (incipient, ingressive)
    • Terminative (egressive)
    • Prospective (intentive)
    • Retrospective
    • Intensive

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Aspectual interactions
  • Functions
    • Foregrounding, narration: perfective
    • Backgrounding, contextual: imperfective
  • Ambiguities
    • John had eaten the popcorn by 1:00.
      (event frame punctuality, reference time punctuality)
    • The dog just ran away.
      (proximal preterite, modal)

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Basic tense concepts
  • The way an event is explicitly indexed for a time frame
  • Event frame: temporally located event
  • Tense locus: contextual, temporal reference point
  • Ordered relations (distal, proximal)
  • Simple (1 event frame) vs. perfect (2 frames)
  • Often tense is inherited; ambiguity can result
    • The man sitting in that chair was rich.
      (relative past, relative present)
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Time intervals
  • Fundamental component to events
  • Time line, number line as analogies, descriptive device, model
    • Moments
    • Subintervals
    • Interval
  • Saturation
    • States è moments
    • Acts è subinterval
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Tense vectoriality
  • Past tense: movement into the completed; bounded, hypothetical, nonactual, counterfactual events
  • Present tense: slightly extended; performatives, in situ narrative, incompleteness, stativity, genericity
  • Future tense: nonactual, hypothetical, inception, prediction, volition, supposition
  • Some languages are tenseless, almost all have only 2 or 3 basic tense distinctions


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Levels of semantic description
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Concept feature decomposition
  • Concepts (entities, events, etc.) composed of primitive, binary features
  • These can be used to classify, distinguish, or identify
    • Man vs. girl vs. filly
    • [Niece,daughter,sister] vs. [nun,woman,girl]
    • [Hen,ewe,cow] vs. [rooster,ram,bull]
    • [Table,chair,pencil] vs. [love,thought,idea]
    • [Table,chair,pencil] vs. [water,dirt,cream]
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Lexical semantics
  • Word meaning
    • Synonymy: youth/adolescent, filbert/hazelnut
    • Antonymy: boy/girl, hot/cold
  • Word senses
    • Polysemy: 2+ related meanings (bright, deposit)
    • Homonymy: 2+ unrelated meanings (bat, file)
  • Connotation: set of ideas, emotions evoked
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Hierarchical lexical relations
  • Hypernymy, hyponymy
    • Animal ßà dog ßà beagle
    • Dog is a hyponym (specialization) of the concept animal
    • Animal is a hypernym (generalization) of the concept dog
  • Meronymy
    • Carburetor <--> engine <--> vehicle

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WordNet: hierarchical lexicon
  • Wide-coverage English dictionary
    • Extensive lexical, concept (word sense) inventory
    • Syncategorematic information (frames etc.)
  • Principled organization
    • Hierarchical relations with links between concepts
    • Different structures for different parts of speech
    • Hand-checked for reliability
  • Utility
    • Designed to be used with other systems
    • Machine-readable database
    • Used as a base/standard by many researchers
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45 WordNet semantic classes

    • (noun.Tops)
    • noun.act
    • noun.animal
    • noun.artifact
    • noun.attribute
    • noun.body
    • noun.cognition
    • noun.communication
    • noun.event
    • noun.feeling
    • noun.food
    • noun.location
    • noun.group
  • 15 Verb classes
    • verb.body
    • verb.change
    • verb.cognition
    • verb.communication
    • verb.competition
    • verb.consumption
    • verb.contact
    • verb.creation
    • verb.emotion
    • verb.motion
    • verb.perception
    • verb.possession
    • verb.social
    • verb.stative
    • verb.weather


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Sense delimitation
  • Fuzziness (rich, tall, green, clean)
  • Typicality, prototypes
    • Bird: robin vs. penguin
  • Lexicalization (snow) (glint, glimmer, glitter, gleam, glisten, glow, glare)
  • Inventories


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Predication
  • Associating property with referent
    • Copular verb
    • Adjectival modifier
    • Relative clause

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Lexicalization
  • The way basic underlying concepts are lexically realized in a language
  • Wide variation crosslinguistically
  • English: motion (V) + path (PP) vs. Romance languages
  • He swam across the river.
    Il traversa la fleuve à la nage
  • L1 verb à L2 prepositional phrase
    L1 preposition
    à L2 verb
  • Limits exist: “flimped”: kissed someone who is allergic to (e.g. John flimped garlic.)
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Thematic roles
  • Function of constituents wrt basic position
  • Assignment
    • Verbs assign theta-roles to arguments
    • Prepositions assign theta-roles to objects
  • Role played by each NP in a sentence
    • Agent: entity that performs an action
    • Theme, Patient: entity that undergoes an action
    • Source, Goal, Location, Path, Instrument
    • Experiencer: perceiver of a cognitive stimulus
    • Stimulus: perceived cognitive stimulus
  • Various theories, various roles
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Diagramming q–role assignment
  • The dog chased the cat up the hill.
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Basic theta-role concepts
  • Theta criterion
  • Relationship with grammar
    • The syntax/semantics interface (mapping)
    • Often direct, sometimes more transparent
  • Ambiguity
    • The witch made the prince a frog.
    • The ducks floated down the river.
    • The anthrax was found by the robot.
    • I smelled the roses.
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Expressing motion
  • Spatial: core meaning is displacement
  • Non-stative event structure
  • Figure/ground dichotomy
  • Displacement
  • Source + goal, location
  • Path
    • Trajectory, reference point (ground)
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Semantic phenomena
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Semantic relationships (1)
  • Paraphrase: re-express identical content
    • The police chased the burglar.
      The burglar was chased by the police.
    • I gave the summons to Eric.
      I gave Eric the summons.
    • Paul bought a car from Sue.
      Sue sold a car to Paul.
    • It is unfortunate that the team lost. Unfortunately, the team lost.
    • The class will begin at 4:00.
      At 4:00, the class will begin.
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Semantic relationships (2)
  • Contradiction: inconsistent, opposites
    • John is a bachelor. John is married.
    • I am happy. I am not happy.
    • Today is Monday. Today is Tuesday.
  • Entailment: S1 necessarily implies S2 is true
    • The park wardens killed the bear. è The bear is dead.
    • Robin is a man. è Robin is a human.
    • Jill and Bill have just gotten married to each other. è Jill and Bill are spouses.
    • David is a Republican. è David is a human.
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Entailments?
  • This is yellow. This is a pencil.
    ?This is a yellow pencil.
  • This is big. This is a whale.
    ?This is a big whale.
  • Lee kissed Kim passionately.
    ?Lee kissed Kim.
    ?Kim was kissed.
    ?Lee touched Kim with her lips.
    ?Lee married Kim.
    ?Kim kissed Lee.
    ?Lee kissed Kim many times.
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Subcategorization
  • What types of complements a word requires/allows/forbids
    • vanish: ø     The book vanished ___.
    • prove: NP    He proved the theorem.
    • spare: NP NP
    • send: NP PP
    • proof: CP
    • curious: PP or CP
    • toward: NP
  • Valence, arity, argument structure, frame, adicity
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Selectional restrictions
  • Close synonymy
    • Small/little
      I have little/*small money.
      This is Fred, my big/*large brother.
  • Animacy
    • My neighbor admires my garden.
      *My car admires my garden.
    • Bill frightened his dog/*hacksaw.
  • Implicit objects in English
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Grammaticalization
  • Realizing semantic information via grammatical categories
    • Morphological information
    • Syntactic information
    • Phonological information
  • Wide variation across languages
  • A major focus of this course
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Semantic ambiguity
  • More than one meaning possible for:
    word/phrase/clause/sentence/utterance
  • Lexically, morphologically, syntactically invariant
  • Everyone loves somebody.
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Non-semantic ambiguity
  • Lexical ambiguity
    • I bought a pen.
    • She bought me a fly.
  • Morphological ambiguity
    • Be careful when drawing these axes.
  • Syntactic ambiguity
    • I saw old men and women.
    • I saw her duck.
    • Visiting relatives can be tedious.
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Semantic ambiguity examples
  • Everyone here speaks two languages.
  • Three men carried a piano.
  • You may not come to my party.
  • Judy wants to marry a Norwegian.
  • Every professor thinks she is busy.
  • A flag was hanging from every balcony.
  • Mary can’t sing.
  • The witch made the prince a frog.
  • John almost walked to the football game.


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Modality
  • Factual status of propositional content
  • Semantic information associated with speaker’s attitudes/opinions
  • Domain/scope: whole expression
  • Often overlaps with mood (syntax)
  • Various values: necessity, evidentiality, possibility, requirement, negation
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Modality (epistemic)
  • Expressing judgment on the factual status and/or likelihood of a state of affairs
  • Connects the speaker to the proposition
  • Possibility/necessity modulated by commitment/evidence
  • Truth relativized to a speaker
  • 2 basic categories: judgments (speculation, deduction) vs. evidentials (overtly qualified)
  • Gradient of certainty (challenge: beneath, open to, above)
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Modality (deontic)
  • Imposition of a state of affairs on individuals
  • Ambiguity
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Negation: properties
  • Denying the factual status of parts of a proposition open to challenge
  • Propositional/sentential vs.  verbal/phrasal
  • Quantifying distance between actuality and nonactuality
    • Comment on speaker’s commitment to proposition
  • Crosslinguistic properties
    • Explicit encoding in some languages
    • Finer distinctions in irrealis
    • Interactions: tense, aspect, definiteness, etc.
74
Negation & scopal interaction
  • Forms: full/aux verb, affixation, doubling, functional variants
  • Scope: wide/narrow, external/internal, sentential/constituent
  • Scope can be narrowed: cooccurrence, movement
  • Interactions: quantifiers
  • Polarity: questions, conditionals, comparison (underlying negation)
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Semantic theories
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Lexical-Conceptual Structure
  • Representation of lexical semantic info
  • Classes: action, process, state, event, property, person, thing


  • Causatives, chassé-croisés, other verb-frame alternations
  • Translation divergence analysis
  • Computer applications (IR, text summarization, MT, etc.)
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Type-Logical Semantics
  • Very tight coupling of syntax, semantics
  • Draws heavily on formal logic principles (proof theory, lambda calculus)
  • Coupling morphosyntax and semantics
  • Parsing languages with complex morphosyntactic structure (Korean, Turkish, Amerindian languages)


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Meaning-Text Theory
  • Developed in USSR in 1960’s, 1970’s
  • Focus is on semsyn/morphophon correspondence
  • Theme/rheme structure
  • Highly mathematical, formalist in nature


  • Translation contrastive analysis
  • NL generation (template-driven, from data)
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Cognitive Grammar
  • Visually, schematically organized
  • Used widely, especially for “exotic” languages
  • No extensive computational implementation


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One cognitive perspective
  • Grammatical categories reflect temporal stability (moreànoun)
    • Cf. events: rapid change in universe
    • Relative atemporality is more precise
  • Scale of temporal stability
  • Abstract nouns almost always derived (e.g. from verbs)
  • Non-productivity of adjectives
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Philosophy and semantics
  • Philosophical methods for describing entities, relations, events, tense, aspect
  • Formal semantics: using tools (logic, inferencing) to prove meaning in a formalized, model-theoretic manner
    • Explores structural properties, compositionality, interfaces with other aspects of language
    • Derives from math, theorem proving, computation systems
    • Widely used in current semantics work

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Linguistic semantics
  • Bottom-up, data-driven, language-oriented approach to semantics
  • Literal meaning approach
  • Empirical field
    • Real-world language examples
    • Structure is crucial to analysis
    • Study of variation, richness of crosslinguistic semantic phenomena
    • Skirts around deep philosophical issues
  • Basic realism as a tenet
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The syntax/semantics interface
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Basic assumptions
  • Syntax, semantics are different modules
  • They are (somehow) related
    • Knowing about one helps knowing about another
  • They involve divergent representations
  • Both are necessary for a thorough treatment of language
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Example applications
  • Anaphor
    • John walked the dog to a store. It barked.
  • Lexical disambiguation
    • I saw a cat doze up the neighbor’s lot.
  • Ellipsis recovery
    • John loves his mother and Jane does ___ too.
  • Modality interpretation
    • Fred may not come to my party.
  • Presupposition
    • He wants ___ to win.
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Two basic approaches
  • Semantics is interpretive
    • Morphology/syntax is prior
    • Map meaning from: syntaxèsemantics
    • Most current linguistic theories
  • Semantics is directly compositional
    • Developed in tandem with syntax
    • Map meaning while: syntax + semantics
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Interpretive semantics
  • Map:
    • NP’s à entities, individuals
    • VP’s à functions
    • S’s à T values
  • Relate objects in the semantic domain via syntactic relationships
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Sample sentence syn/sem
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Parsing (NL-Soar)
90
Generation (NL-Soar)
91
Computational semantics
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Goals
  • Describe semantics as an abstract, observable, formal system
  • Develop models of implicit knowledge, cognitive processing, and linguistic information
  • Apply these models in real-world situations
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Extreme approaches
  • I want to process language no matter how I have to do it. (engineering)
    • No intended cognitive plausibility
    • Airplanes don’t flap their wings.
  • I want to process language just like a human does it. (psycholinguistic)
    • Cognitive plausibility
    • You can’t be like a human otherwise.


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Semantic representations
  • Ways of representing concepts
    • Basic entities, actions
    • Relationships between them
    • Compositionality of meaning
  • Some are very formal, some very informal
  • Various linguistic theories might involve different representations
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Sample FUF data element
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Another FUF example
  •   "Saturday night, Karl Malone scored 28 points with his hands."
  •   ((cat clause)
  •    (tense past)
  •    (process ((type material) (effect-type creative) (lex "score")))
  •    (partic ((agent ((cat compound-proper)
  •   (gender masculine)
  •   (head ((cat person-name)
  •          (first-name ((lex "Karl")))
  •          (last-name ((lex "Malone")))))))
  •     (created ((cat measure)
  •       (quantity ((value 28)))
  •       (unit ((lex "point")))))))
  •    (pred-modif ((instrument ((cat pp)
  •       (np ((cat common)
  •                  (number plural)
  •            (possessor ((cat personal-pronoun)
  •                        (index {^5 partic agent index})))
  •    (head ((lex "hand")))))))))
  •    (circum ((time ((cat date)
  •    (day-name ((lex "Saturday")))
  •    (day-part ((lex "night")))
  •    (position header)))))))
97
NITROGEN sample
  • (H / |possible<latent|
  •   :DOMAIN (H2 / |obligatory<necessary|
  •             :DOMAIN (E / |eat,take in|
  •                       :AGENT YOU
  •                       :PATIENT (C / |poulet|))))
  • LATTICE STATS:
  •   383 nodes, 1116 arcs, 18755700 paths,
  •   54 distinct unigrams, 446 distinct bigrams,
  •   2154 distinct trigrams.
  • you may have to eat chicken .
  • you might have to eat chicken .
  • you could have to eat chicken .
  • you could be required to eat chicken .
  • you may be required to eat chicken .
  • you might be required to eat chicken .
  • you may have to be eating chicken .
  • you might have to be eating chicken
  • you could have to be eating chicken .
  • you could be obliged to eat chicken .
  • you may be obliged to eat chicken .
  • you might have to eat a chicken .
  • you could have to eat a chicken .
  • you may have to eat the chicken .
  • you might have to eat the chicken .
  • you could have to eat the chicken .
  • you could be having to eat chicken .
  • you may have to eat the chickens .
  • you might have to eat the chickens .
  • you could have to eat the chickens .
  • you could be required to be eating chicken .
  • you may be required to be eating chicken .
  • you might be required to be eating chicken .
  • Consumptions of an chicken by you could be being requirement .
  • That the consumption of the chicken by you was requirements was possibilities .
98
KANT MT overview
99
 
100
Modeling syntactic processing
  • NL-Soar cognitive modeling system for natural language
  • Most complete X-bar model consistent with lexical properties, syntactic principles
  • Non-productive partial structures are later discarded
  • Input for semantic processing
101
Modeling semantic processing
  • Also done on word-by-word basis
  • Uses lexical-conceptual structure
  • Leverages syntax
  • Builds linkages between concepts
  • Previous versions used 8 semantic primitives
    • Coverage useful but inadequate
    • Difficult to encode adequate distinctions
  • WordNet lexfile names now used as semantic categories
102
Preliminary semantic objects
  • Pieces of conceptual structure
  • Correspond to lexical/phrasal constructions in syntactic model
  • Compatible pieces fused together as appropriate
103
Collocation constraints
  • Enforce compatibility of pieces of semantic model
  • Reflect limited disambiguation
  • Based on semantic classes
  • Ensure proper linkages, reject improper ones
  • Implemented as preferences for potential attachments
104
Final semantic model
  • Most fully connected linkage
  • Includes other sem-related properties not illustrated here
  • Serves as input for further processing (discourse/dialogue, extralinguistic task-specific functions, etc.)
105
Semantic disambiguation
  • Word sense
    • Choosing most correct sense for a word in context
    • Problem: WordNet senses too narrow (large # of senses)
      • Avg. 4.74 for nouns (not a big problem)
      • Avg. 8.63; high of 41 senses for verbs (a problem)
  • Semantic classes
    • Select appropriate WordNet semantic class of word in context
    • An easier, more plausible task


106
Sem constraint for #29 v-body
  • Most frequent verbs in class:
  • wear, sneeze, yawn, wake up
  • (most frequent) Subjects:
    • People
    • Animals
    • Groups
  • Direct Objects:
    • Body Parts
    • Artifacts
  • Indirect Objects: none


  • Subject Constraint
  • sp {top*access*body*external
  •   (state <g> ^top-state <ts> ^op <o>)
  •   (<o> ^name access)
  •   (<ts> ^sentence <word>)
  •   (<word> ^word-id.word-name <wordname>)
  •   (<word> ^wndata.vals.sense.lxf v-body)
  • -->
  •   (<word> ^semprofile <sempro> + &)
  •   (<sempro> ^category v-body ^annotation verbclass + & ^psense <wordname> ^external <subject>)
  •   (<subject> ^category *
  •      ^semcat n-animal + &
  •      ^semcat n-person + &
  •          ^psense * ^internal *empty*) }
107
Sample sentence: the woman yawned
(basic case: most frequent senses succeed.)
  • Syntax:
    • first tree works.


  • Semantics:
    • v-body & n-person match.
    • v-stative never tried.
108
Example #2:  The chair yawned
(most frequent noun sense inappropriate)
  • Syntax:
    • chairverb rejected
    • chairnoun accepted
  • Semantics:
    • chairverb senses rejected
    • n-artifact incompatible w/ v-body
    • n-person accepted
109
Example #3:  The crevasse yawned.
(most frequent verb sense inappropriate)
110
THE BEGINNING