14
June 12, 2003 AQUAINT 18 Month Meeting San Diego CA Natural Language Querying of the Semantic Web SRI International Information Science Institute
June 12, 2003 AQUAINT 18 Month MeetingSan Diego CA
Natural Language Queryingof the
Semantic Web
SRI International
Information Science Institute
June 12, 2003 AQUAINT 18 Month MeetingSan Diego CA
Beyond Single QuestionSingle Source Answers
• Most question answering systems to date have been limited to querying a single kind of source, a corpus of texts, for answers to a given question.
• Most have been limited to answering single questions with single factual answers.
• Aim: to move beyond these limits Use of multiple (semi-)structured sources Information-gathering dialogues
June 12, 2003 AQUAINT 18 Month MeetingSan Diego CA
QUARK
• Natural language front end Gemini: Unification Grammar (CFG backbone)
• Mediated by powerful reasoning tool SNARK: Full FO Theorem Prover
• Powerful resource description and access capabilities OAA: Intelligent delegation-based middleware
• Visualization capabilities TerraVision: Terrain Viewer
June 12, 2003 AQUAINT 18 Month MeetingSan Diego CA
Multiple Sources
• Access to multiple knowledge sources ADL Gazetteer CIA World Factbook NASA data sources TextPro IE engine
June 12, 2003 AQUAINT 18 Month MeetingSan Diego CA
Goal: To Integrate DAML Search into QUARK
• Agent Semantic Communications Service (ASCS)
• Developed by Teknowledge.
• Searches the Web for DAML pages.
• Provides GUI for search.
• Provides inference capability aimed at broadening and relaxation of queries.
June 12, 2003 AQUAINT 18 Month MeetingSan Diego CA
The ASCS Search Page
June 12, 2003 AQUAINT 18 Month MeetingSan Diego CA
ASCS: A Use Case
pred: capital
arg1:
arg2: Syria
?x
Searches entireSemantic Web
Also conjunctive queries: population of capital of Syria
To find the capital of Syria, a user must input
Problem: Doesn’t support natural language input; using ASCS requires knowing some logic.
capital(?x,Syria)
June 12, 2003 AQUAINT 18 Month MeetingSan Diego CA
How to Use ASCS in QUARK
• Questions parsed by Gemini to yield logical form.• Logical form submitted to SNARK as conjecture.• Conjecture proved in application-domain theory.• Capabilities of ASCS and other sources advertised in
theory.• ASCS provided with OAA wrapper.• Resources invoked as appropriate by procedural
attachment.• Answer, as extracted from proof.
• Presented textually• Visualization tool invoked
June 12, 2003 AQUAINT 18 Month MeetingSan Diego CA
“Show the capitals of Islamic countries that border Iraq.”
Logical form produced by Gemini:
(and country (?x) islamic (?x) bordering-relation (?z)goal (?z, iraq) source (?z, ?x) capital-of (?u, ?x) show (?v) patient (?v, ?u))
Answer: ?v
June 12, 2003 AQUAINT 18 Month MeetingSan Diego CA
Conjecture decomposed by SNARK
To show a country is Islamic, use the axioms in the application-domain theory:
if religions (?country, Muslim, ?percent)
and ?percent > 50
then islamic (?country)
if (SunniMuslim ?x, then Muslim ?x)
A country that is more than 50 percent Muslim is Islamic.
A SunniMuslim is a Muslim.
June 12, 2003 AQUAINT 18 Month MeetingSan Diego CA
ASCS Reveals Basic Facts
• borders(Iraq, Syria)
borders(Iraq, Turkey), …..
• religions(Syria, SunniMuslim, 74)
religions(Syria, Christian, 10), …
• capital(Syria, Damascus)
June 12, 2003 AQUAINT 18 Month MeetingSan Diego CA
Other Agents Reveal other Facts
• Alexandria Digital Library Gazetteer:
place-to-latlong(Damascus, capital, Syria;
33.5, 36.3)
June 12, 2003 AQUAINT 18 Month MeetingSan Diego CA
Answer visualization by Terrain ViewerDamascus (capital),Syria; 33.5,36.3
June 12, 2003 AQUAINT 18 Month MeetingSan Diego CA
Future Plans
• To move beyond single, one-off questions to scenario-based information-seeking dialogues.
• Scenario description presents a sketch of a situation/problem; much is left unsaid.
• To be filled out by a combination of application-domain theories and clarification/expansion dialogues.
• Ground further question-answering on the resulting situation model.
