1 / 19

Lexical databases as resources for linguistic creativity: Focus on metaphor

Lexical databases as resources for linguistic creativity: Focus on metaphor. Birte Lönneker University of Hamburg, Germany Research Center of the Slovenian Academy, Ljubljana. Introduction. Metaphor is a form of linguistic creativity: the more novel, the more creative

gail-brooks
Télécharger la présentation

Lexical databases as resources for linguistic creativity: Focus on metaphor

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Lexical databases as resources for linguistic creativity: Focus on metaphor Birte Lönneker University of Hamburg, Germany Research Center of the Slovenian Academy, Ljubljana LREC 2004 Linguistic Creativity, 29 May 2004 @ Birte Lönneker

  2. Introduction • Metaphor is a form of linguistic creativity: the more novel, the more creative • There are several types of novel metaphors • Novel metaphors are rare • By studying conventionalized metaphors and their novel extensions, we can learn more about creative metaphors LREC 2004 Linguistic Creativity, 29 May 2004 @ Birte Lönneker

  3. A conceptual metaphor CHANGE IS MOTION • Conventional lexical metaphors illustrate the metaphorical mapping: • The Financial Times 30-share index tumbled34.9 to [...]. • [...] profit margins fellto 3.9% from 5.8% a year earlier, as general expenses soarednearly sevenfold. • [...], service-industry employment roseabout 200,000, against a 2.7 million dropin goods-producing jobs. Change abstract size Change physical location LREC 2004 Linguistic Creativity, 29 May 2004 @ Birte Lönneker

  4. Systems for textunderstanding and generation need knowledge resources “general expenses soared” to soar1 [SUBJ: airplane, flying object] to soar2 [SUBJ: abstract entity (with location on abstract scale)] LREC 2004 Linguistic Creativity, 29 May 2004 @ Birte Lönneker

  5. Lexical databases as resources Questions: • To which extent do current lexical databases provide information on conventional metaphor? (... which is creatively extensible) • Which representation structures • do exist? • are still needed? LREC 2004 Linguistic Creativity, 29 May 2004 @ Birte Lönneker

  6. Examples of lexical databases • Princeton WordNet: English, ongoing • WN 2.0: 115,000 concepts • free! • EuroWordNet: eight European languages • ca. 15,000 concepts for German • ca. 23,000 concepts for French • available from ELRA/ELDA LREC 2004 Linguistic Creativity, 29 May 2004 @ Birte Lönneker

  7. Synsetsare sets of synonyms or near-synonyms referring to the same concept, e.g. {tumble, topple} (the concept of ‘fallingdown, as if collapsing’) Relationscharacterize the way in which two synsets are connected,e.g. {tumble, topple} HAS_HYPERONYM {descend, fall, go down, come down} WordNet structuring principles LREC 2004 Linguistic Creativity, 29 May 2004 @ Birte Lönneker

  8. MOTION CHANGE Lexical Metaphors in WordNet 2.0 ANTONYMY {travel, go, move, locomote} {change magnitude} {descend, fall, go down, come down} {decrease, diminish, lessen, fall} ANTONYMY {decline, go down, wane} {tumble, topple} {drop} {drop} {tumble} {rise, lift, arise, move up, go up, come up, uprise} {increase} {wax, mount, climb, rise} {soar, soar up, soar upwards, surge, zoom} [...] {soar}

  9. First consequences for knowledge-based systems • Knowledge Acquisition: • Lexical databases as resource for representing the structure of the source and target domain • Evaluation: • Reference to a common general lexical resource can facilitate the comparison of different systems that deal with metaphor. LREC 2004 Linguistic Creativity, 29 May 2004 @ Birte Lönneker

  10. The Hamburg Metaphor Database • Currently, wordnets do not directly relate conceptual domains that underly metaphoricity. • The mapping is reflected only indirectly by parallel polysemy (if at all). • Aim of the Hamburg Metaphor Database: Study how information on metaphors could better be represented in Wordnets LREC 2004 Linguistic Creativity, 29 May 2004 @ Birte Lönneker

  11. Hamburg Metaphor Database Resources • Corpora: Collected for Master Theses • Languages: German and French • Lexical database: EuroWordNet in German and French • Domain names: Free list of conceptual domains and mappings (Lakoff et al. 1991) LREC 2004 Linguistic Creativity, 29 May 2004 @ Birte Lönneker

  12. Hamburg Metaphor Database Methodology • Identify metaphorically used word in corpus texts • Enter corpus context (sentence, phrase) • Annotate the lexical metaphor with • synset information from EuroWordNet • domain information from metaphor list • (additional) domain information in German LREC 2004 Linguistic Creativity, 29 May 2004 @ Birte Lönneker

  13. Hamburg Metaphor DatabaseExample LREC 2004 Linguistic Creativity, 29 May 2004 @ Birte Lönneker

  14. Case Study • Input: 22 results from the Hamburg Metaphor Database for the source domain BUILDING (BAUWERK) • Target domains: CREATING (ACTION), ORGANIZATION, ... • Lexical metaphors: e.g. architect, construction, debris, foundation, pillar LREC 2004 Linguistic Creativity, 29 May 2004 @ Birte Lönneker

  15. destroy create creator Representation of the BUILDING Source Domain in EuroWordNet {zerstören:1} {erschaffen:1 erzeugen:2 machen:5 schaffen:3} {créateur:1} INVOL- VED_ AGENT {zertrümmern:N in Trümmer legen:N} create {anfertigen:1 fabrizieren:1 fertigen:1 herstellen:3 ...} {créer:1 faire:13} INVOLVED_ RESULT architect debris {Architekt:1 ...} {architecte:1 designer:1 ...} {Trümmer:N} build XPOS_NEAR_ SYNONYM {bauen:2} {fabriquer:4 construire:2 ...} {créer:13 réaliser:3} {Aufbau:N} CO_ AGENT_ RESULT INVOLVED_ RESULT {bâtir:N ériger:1 élever:8 ...} foundation building part building {Fundament:1 Grundfeste:N} {Gebäudeteil:1} {élément de construction:1} {Gebäude:1} {édifice:1 ... construction:6} HAS_ MERO_ PART {Fassade:N} {Säule:N} {socle:N}

  16. More consequences for knowledge-based systems + • Much more relation types in EuroWordNet than in Princeton WordNet • Therefore, domain-internal relations can be denser -- • Polysemy not represented in EuroWordNet: for most lexemes, we find only literal meanings • Some relation types not sufficiently instantiated LREC 2004 Linguistic Creativity, 29 May 2004 @ Birte Lönneker

  17. Mapping • Relate central synset of source domain to corresponding concept in target domain • directly in lexical resource (EWN) • Target domain: same structure as source domain • Target domain: lexical items have attested or potential metaphorical meaning, • related to that of the central synset in the same way as in the source domain. LREC 2004 Linguistic Creativity, 29 May 2004 @ Birte Lönneker

  18. destroy create creator {zerstören:1} {erschaffen:1 erzeugen:2 machen:5 schaffen:3} {créateur:1} INVOL- VED_ AGENT {zertrümmern:N in Trümmer legen:N} create {anfertigen:1 fabrizieren:1 fertigen:1 herstellen:3 ...} {créer:1 faire:13} INVOLVED_ RESULT architect debris {Architekt:1 ...} {architecte:1 designer:1 ...} {Trümmer:N} build XPOS_NEAR_ SYNONYM {bauen:2} {fabriquer:4 construire:2 ...} {créer:13 réaliser:3} The BUILDING Domain in EWN {Aufbau:N} CO_ AGENT_ RESULT INVOLVED_ RESULT {bâtir:N ériger:1 élever:8 ...} foundation building part building {Fundament:1 Grundfeste:N} {Gebäudeteil:1} {élément de construction:1} {Gebäude:1} {édifice:1 ... construction:6} HAS_ MERO_ PART {Fassade:N} {Säule:N} {socle:N} {…:N}

  19. Instead of a conclusion... Further topics: • Literal-figurative inconsistencies in current lexical databases! • World knowledge (relations) in lexical resources? • Your questions!? LREC 2004 Linguistic Creativity, 29 May 2004 @ Birte Lönneker

More Related