EMASTERS SCHOOL Vincent Spinc le MAI-SLT 2002 A syntactic and semantic treatment of ergativity in a system network grammar Vincent Spinc le

EMASTERS SCHOOL Vincent Spinc le MAI-SLT 2002 The Company Language And Computing Zonnegem, Belgium 30 employees Focus: medical market Products: automatic text indexing, information retrieval, medical ontology

EMASTERS SCHOOL Vincent Spinc le MAI-SLT 2002 The Linguistics Department building a computational grammar for English to analyse medical abstracts/patient reports in order to improve information retrieval Goal: text understanding (so a correct grammatical AND conceptual analysis) Method: grammar formalism = Systemic- Functional Grammar (SFG) My task description: adjust the grammar to include correct parsing of ergativity (plus conceptual representation); -mental verbs -aspectual verbs

EMASTERS SCHOOL Vincent Spinc le MAI-SLT 2002 The Grammar Formalism System networks design of the grammar: features, AND-gates, OR- gates, realizations lexical-verb intransitive-verb monotransitive-verb ditransitive-verb transitive-verb Compl: +1 Compl: {noun or {acc and pronoun}}

EMASTERS SCHOOL Vincent Spinc le MAI-SLT 2002 Dependency dependency vs constituency

EMASTERS SCHOOL Vincent Spinc le MAI-SLT 2002 Linkbase Concepts connected by Linktypes

EMASTERS SCHOOL Vincent Spinc le MAI-SLT 2002 concepts, not lemma’s: BIOPSY OF LIVER IS-A: biopsy HAS-SOURCE: liver HAS-THEME: liver biopsy tissue linguistic descriptions of processes: material processes, being processes, etc. Concept modeling in Linkbase

“The doctor that treated the patient now has Cancer” MEDICCANCER Has-HC-Phenom MEDICAL- PROCEDURE Has- Actor Has- Actee PATIENT

EMASTERS SCHOOL Vincent Spinc le MAI-SLT 2002 Ergativity examples: (1a) The bookkeeper killed his wife. (1b) *His wife killed. (2a) The doctor opened the valve. (2b) The valve opened. How introduced into the grammar? - list ergative verbs - new category in lexicon: ergative verb - new direct object: ErgObj

EMASTERS SCHOOL Vincent Spinc le MAI-SLT 2002 Ergativity(2) difference with normal transitive verbs: -syntactically: limited -main difference: semantically: - characterization of ergativity in terms of different process-participant relations (Davidse 1999): Transitive sentences: actor/goal Ergative sentences: ergative- instigator/ergative medium

EMASTERS SCHOOL Vincent Spinc le MAI-SLT 2002 Ergativity (3) INVESTIGATION- PROCESS Actee (goal) Actor LINKBASE Subject Transitive- verb syntax Object examines the patient The doctor

EMASTERS SCHOOL Vincent Spinc le MAI-SLT 2002 IMPROVING- PROCESS HAS- ERGATIVE- MEDIUM HAS- ERGATIVE- INSTIGATOR LINKBASE Subject Ergative- verb syntax ErgObj improves the patient The doctor Ergativity (4)

EMASTERS SCHOOL Vincent Spinc le MAI-SLT 2002 Ergativity (5) IMPROVING- PROCESS HAS- ERGATIVE- MEDIUM LINKBASE Subject Ergative- verb syntax improved The patient

EMASTERS SCHOOL Vincent Spinc le MAI-SLT 2002 Conceptual definition of ergativity transitive verbs: material process: criteria list: has-actor has-actee ergative verbs: ergative process: criteria list: has-instigator has-medium

EMASTERS SCHOOL Vincent Spinc le MAI-SLT 2002 LINKBASE: ERGATIVE PROCESS The doctor increased the pressure. The pressure increased. Het virus infecteert het weefsel La pression est augmentée. Le docteur augmente la pression Het weefsel infecteert. SEMANTIC MAPPING (language-dependent)

EMASTERS SCHOOL Vincent Spinc le MAI-SLT 2002 Conclusion Develop a system which handles ergativity in the grammar System network grammar: wide coverage, transparent grammar Practical use of theoretical linguistic research Further development: develop a semantic mapping component, add probabilistic parsing to reduce number of parses