Exploiting Sublanguage and Domain Characteristics in a Bootstrapping Approach to Lexicon and Ontology Creation

Transkript

1 Exploiting Sublanguage and Domain Characteristics in a Bootstrapping Approach to Lexicon and Ontology Creation Otto-von-Guericke University Magdeburg Department of Knowledge Processing and Language Engineering

2 Content of the Talk Motivation Pathology Reports Co-occurence Analysis and Clustering Ontology Creation Discussion

3 Motivation document processing (e.g. text mining) in a new domain lexical gaps sublanguage gaps conceptual gaps... support for lexicon and ontology creation needed

4

5 Core Idea support creation of initial lexicon and ontology starting point: sublanguage analysis e.g. pathology: telegrammatic style syntactic structure e.g.: <NOUN><ADJ><FULLSTOP> semantic patterns e.g.: <ANATOMIC-ENTITY><ATTRIBUTE-VALUE> <FULLSTOP>

6 Beyond simple Patterns examples of syntactically processed structures simplepatterns Gehoergänge frei. Augen sind geschlossen. patterns with modifier and negation Brustkorb nicht sehr breit. patterns with coordination Beckengeruest festgefuegt und unversehrt. Akute und chronische Erweiterung des Herzens. Rippen und Wirbelsaeule intakt. Leber und Niere ohne Besonderheiten.

7 Beyond simple Patterns structures not yet covered coordinated structures with truncations Augenober- und unterlid Wangen- und Kinnpartie contextual interpretation Hirngewicht 1490 g. Windungen abgeflacht, Furchen verstrichen.... in progress: mapping to semantic interpretation attribute-value-structures

8 Beyond simple Pattern dimensions modifiers: etwas bernsteinfarbene Flüssigkeit negation: nicht sehr muskelkräftig coordination: Beckengerüst unversehrt und fest gefügt noun, noun groups: Bauchteil der großen Körperschlagader

9 Corpus based Analysis current corpus: ~ texts (autopsy reports) co-occurence analysis and clustering of adjectives adverbs verbs nouns, noun phrases preposition phrases results as basis for lexicon and ontology creation

10 Adjectives: Excerpts from Clustering altersentsprechend: Vorsteherdruese {35}, Innere Geschlechtsorgane {5}, Brustdruesenkoerper {3}... frei: Nierenbecken {83}, Gangsystem {81}, Herzohren {78}, Kehlkopfeingang {77}, Harnleiter {73}, Grosser Ausfuehrungsgang {57}, Lungengefaesse {56}, Gehoergaenge {56}, Nasenoeffnungen {32}, Die Lungengefaesse {8}, Hauptausfuehrungsgang {4}, Ausfuehrungsgang {4}, Die Gefaesse {3}... intakt: Schulterblaetter {81}, Herzbeutel {80}, Dornfortsaetze {78}, Brueckenvenen {70}, Gelenk zwischen Schaedelgrund {57}, Halswirbelsaeule {57}, Das Schaedeldach {53}, Kehlkopfgeruest {30}, Zwerchfelle {27}, Brustbein {24}, Zaehne {17}, Schaedeldach {13}, Wirbelsaeule {10}, Kehlkopfgeruest auf Praeparation {7}, Zwerchfell {7}, Kehlkopfgeruest einschliesslich Zungenbein {7}, Rippen {6}, Kehlkopfgeruest nach Praeparation {6}, Die Brueckenvenen {5}, Dornfortsaetze der Wirbelsaeule {5}, Der Herzbeutel {4}, Schluesselbeine {4}, Beide Zwerchfelle {3}, Die Zwerchfelle {3}... spiegelnd: Herzueberzug {75}, Lungenueberzug {43}, Der Lungenueberzug {22}, Der Herzueberzug {7}...

11 Excerpts from Clustering Nouns:... Harte Hirnhaut:glaenzend {41}, perlmuttergrau {35}, grauweiss {15},... Herzbeutel: intakt {80}, grauweiss {5}, unversehrt {4}, nicht-intakt {3}... Nierenbecken: frei {83}... Vorsteherdruese: altersentsprechend {35}, regelrecht {14}, ohne-besonderheiten {5}... Weiche Hirnhaeute: zart {32}, durchscheinend {31}, glasig-durchscheinend {3}...

12 Supporting Ontology Creation characteristics of adjectives quasi-synonyms: altersentsprechend vs. regelrecht antinomy: innere vs.äußere harte vs. weiche discrete values: Mund: geschlossen, spaltweit geöffnet, spaltförmig geöffnet, geöffnet

13 Concept Recognition detection of multi word concepts: candidate pattern: <ADJ> <NOUN> with different properties Harte Hirnhaut perlmuttergrau. (m.c.: dura mater) Weiche Hirnhaut zart. (m.c.: leptomeninx) with the same properties obere Extremitäten (m.c.: upper limbs) untere Extremitäten (m.c.: lower limbs) but: flüssige Galle as in: In der Gallenblase flüssige Galle. liquid bile as in: In the gallbladder liquid bile.

14 Adjectives: generic vs. specific distinguish between generic adjectives and more specific ones generic: broadly applicable intakt unauffällig regelrecht more specific: usage restrictions frei: tubes spiegelnd: surfaces of inner organs muskelkräftig: muscles

15 Analysis of Pathology Reports text: linguistic unit 1 linguistic unit 2 linguistic unit 3... linguistic unit n finding 1 finding 2 finding 3... finding n knowledge level: conclusions about: cause of death natural vs. unnatural external impacts?

16 Semantic Interpretation: Synonyms and linguistic units Paraphrases... ohne Besonderheiten... regelrecht... altersentsprechend... unauffällig Finding: OK

17 Semantic Interpretation: Problems idiosyncratic terms and interpretations Im Herzbeutel bernsteinfarbene Flüssigkeit. OK interactions with modifiers Im Herzbeutel etwas bernsteinfarbene Flüssigkeit.?

18 Ontological Relations property value Surface-of kidney smooth is-a relation Liver is-a organ. part-of (substructure) Mucous membrane part-of stomach n-ary relations Head not abnormally moveable

19 Semantic Classification unknown terms co-occuring with specific adjectives e.g.: Arme, Beine -> muskelkräftig (obere untere) Extremitäten? muskelkräftig unknown terms synonymy?

20 Future Work corpus: >1000 protocols transfer to other domains: IE from WWW pages (profiles of casting companies) car accident reports analysis of busines plans...

21 What is generalisable? Methodology initial sample pattern analysis: from simple to complex initial lexicon grammar based processing clustering of results and cluster analysis extension to larger corpus

22 Thanks! It s time for discussion!

23 Related Work WordNet GermaNet UMLS Ontosaurus SIMPLE Paul Buitelaar