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Klik for at redigere titeltypografi i masteren,Klik for at redigere teksttypografierne i masteren,Andet niveau,Tredje niveau,Fjerde niveau,Femte niveau,*,*,From Allesandro Lenci,1,Linguistic Ontologies,Mikrokosmos (Nirenburg, Mahesh et al.),Generalized Upper Model,(Bateman et al.),WordNet,(Miller, Fellbaum et al.),EuroWordNet,(Vossen et al.),Sensus,(Hovy, Knight, et al.),SIMPLE,(Calzolari, Lenci et al.),2,The Relational Hierarchy,The Relational Hierarchy,3,Linguistic Ontologies,design issues,Network based,hierarchy (taxonomy),WordNet,heterarchy,SIMPLE,Frame based,Mikrokosmos,Generative Lexicon,4,part,Isa,Isa,Isa,fly,Used_for,Used_for,airplane,Is_a_part_of,bird,Is_a_part_of,building,Is_a_part_of,Ala,(wing),SemU: 3232,Type: Part,Part of an airplane,SemU: 3268,Type: Part,Part of a building,SemU: D358,Type: Body_part,Organ of birds for flying,SemU: 3467,Type: Role,Role in football,player,Isa,Agentive,Linguistic Ontologies,SIMPLE,make,Agentive,5,Top,Formal,Constitutive,Agentive,Telic,Is_a,Is_a_part_of,Property,Contains,Created_by,Agentive_cause,Indirect_telic,Activity,Instrumental,Is_the_habit_of,Used_for,Used_as,.,.,Linguistic Ontologies,SIMPLE heterarchy of relations,6,Linguistic Ontologies,frames,Mikrokosmos,Generative Lexicon,7,Concepts, Words and Meanings,Two Views on Semantic Content,Top-down approach,The semantic content of a word is defined by its coordinates within an,ontology of concepts,Bottom-up approach,The semantic content of a word is defined by the,distributional co-occurrence patterns,of that word,Semantic knowledge,NLP,KR&M,8,Concepts, Words and Meanings,Top-down view,Words express meanings corresponding to,semantic types,Semantic types are defined by a,symbolic system,(,ontology,) of conceptual categories independent of (and yet linked to) the concrete uses of words in context,The actual instantiation of a meaning in context is a,token,of a given semantic type,9,The Top-Down View,Semantic type systems (ontologies) provide,explicit, directly processable representations of word content,Discrete,and,symbolic,view of lexical meaning,Support inferential mechanisms,Language independent representation (e.g. multilinguality, etc.),Complex concepts are explained by symbol syntactic combinations,Respond quite nicely to the language engineering demands for reusable semantic resources in machine readable form,Linguistic ontologies are “hand-made”,10,Concepts and Symbols,Traditional view of concepts (Barsalou 1992):,amodal symbols,de-situated,invariant through experiential situations,11,Meanings and Symbols,Traditional view of semantic types:,context-free,discrete,invariant through linguistic contexts,represented by “language-extrinsic” logical forms,car,12,Polysemy,bank,1,(Hanks 2000),IS AN INSTITUTION,IS A LARGE BUILDING,FOR STORAGE,FOR SAFEKEEPING,OF FINANCE/MONEY,CARRIES OUT TRANSACTIONS,CONSISTS OF A STAFF OF PEOPLE,bank,2,IS LAND,IS SLOPING,IS LONG,IS ELEVATED,SITUATED BESIDE RIVER,(Pustejovsky 1995),13,Perceptual Symbols,(Barsalou 1999),a frame of car integrating different perceptual symbols,Concepts as simulators,generating mechanisms,producing simulations,of,instances,14,Linguistic Symbols,“Like a perceptual symbol, a linguistic symbol is not an amodal symbol, nor does an amodal symbol ever develop in conjunction with it. Instead, a linguistic symbol develops just like a perceptual symbol. As selective attention focuses on spoken and written words, schematic memories extracted from perceptual states become integrated into simulators that later produce simulations of these words in recognition, imagination and production”,(Barsalou 2000:592),15,Semantic Multidimensionality,No Functionality,dog, stone, man,Relational,member, father, bishop,Functionality,player, lawyer, chair,Artifactuality,chair, airplane, etc.,Temporal duration,pedestrian, passenger,Agentivity,killer, lawyer,Concepts expressed by lexical items are multidimensional entities,16,Conceptual Complexity,Concepts differ for their internal structural complexity,(,cf,.,Keil,1989),uomo,“man”,musicista,“musician”,orchestrale,“orchestra player”,natural kind,natural kind + functionality,natural kind + functionality + relational,17,Dimensions of Meaning,Concepts are systems of dimensions,words lexicalize the concept, its dimensions, the possible values of these dimensions,Ontology are system of concepts,Ontology Learning vs. Concept Learning,18,
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