Conjunctive Query Answering in Distributed Ontology Systems for Ontologies with Large OWL ABoxes Xueying Chen and Michel Dumontier Carleton University Ottawa, Canada 10/24/2009 OWLED 2009 http://www.webont.org/owled/2009/schedule.html

Motivation Increasingly larger KBs Ontologies (+200; range of expressivity) NCBO Bioportal Facts (10 2 ->10 10 ) yOWL, PGKB, Bio2RDF 10/24/2009 OWLED 2009

Increasingly larger KBs

Ontologies (+200; range of expressivity)

NCBO Bioportal

Facts (10 2 ->10 10 )

yOWL, PGKB, Bio2RDF

Objective Obtain relevant facts to answer a question in distributed environments 10/24/2009 OWLED 2009

Obtain relevant facts to answer a question in distributed environments

10/24/2009 OWLED 2009

Procedure Over a normalized Tbox/Rbox Given a query, Construct q’ by unfolding non-atomic concepts and roles in q Retrieve the relevant facts from each node using the concepts and roles in q’ Evaluates the given query over the new ontology fragment (Tbox + Rbox + extracted facts) Return the answers to user 10/24/2009 OWLED 2009

Over a normalized Tbox/Rbox

Given a query,

Construct q’ by unfolding non-atomic concepts and roles in q

Retrieve the relevant facts from each node using the concepts and roles in q’

Evaluates the given query over the new ontology fragment (Tbox + Rbox + extracted facts)

Return the answers to user

TODO Identify the expressivity of OWL for which the technique returns complete answers + prototype Thanks to the reviewers that provided high quality constructive feedback! 10/24/2009 OWLED 2009

Identify the expressivity of OWL for which the technique returns complete answers

+ prototype

Thanks to the reviewers that provided high quality constructive feedback!