Panel on Knowledge Repositories

1
Panel on Knowledge Repositories

• Organizer Chitta Baral
• chitta_at_asu.edu
• Panel members Michael Gelfond
• Vladimir Lifschitz

2
What do I mean by a knowledge repository?

• A collection of knowledge modules.
• That can be used by knowledge base developers.
• Similar to Java or C libraries.
• But building a knowledge repository
• poses a lot more challenges
• to be discussed in later slides.
• and will be much larger in size.

3
Why do we need knowledge repositories?

• Reasoning with Knowledge and learning knowledge
  is the essence of AI.
• Evident from the meaning of intelligence in a
  dictionary
• Lot of progress in Knowledge Representation.
• Especially with respect to AnsProlog (logic
  programming with answer set semantics)
• A core language with many suggested extensions
• A large body of theoretical results
• Many implementations
• Many applications

4
But we need to

• Go beyond
• Writing knowledge axioms from scratch
• Small knowledge bases
• Be able to build large knowledge bases without
  starting from scratch.
• Make it easier to build knowledge bases.
• Reuse knowledge modules developed by others.
• Make knowledge bases part of most AI systems.

5
Applications and Impacts of Knowledge Repositories

• Question answering systems
• Text John took a flight from Rome to Paris 6
  hours ago?
• Question Where is John now? Where is his wife
  who saw him off at the airport?
• Any system that needs to use common-sense
  reasoning.
• Any system that needs to reason with knowledge in
  one or many domains.

6
Is this a blue sky dream?

• Not really?
• Wordnet (http//wordnet.princeton.edu/)
• An electronic repository of words and their
  meanings has been very useful.
• It took a lot of work to get built.
• A knowledge repository will need a lot more work.

7
What does building a Knowledge Repository involve?

• A large body of Knowledge modules possibly
  grouped in packages
• Common sense modules
• Domain specific modules
• High level modules actions, time, space, etc.
• Methodology to facilitate building modules
• Inheritance, encapsulation, modeling languages,
  etc.
• Interface mechanisms similar (in functionality)
  to interface mechanisms in Java, C etc.

8
Existing efforts CYC

• CYC a pioneer
• Possible IP and legal issues.
• subsets (ResearchCYC) need signing of a lot of
  legal documents.
• CYC s language is proprietary and untested
  outside of CYC. (mostly unpublished outside).
• But if this can be overcome, then it could be a
  good starting or reference point.

9
Existing efforts CYC

• CYC our effort
• Celera effort Open Genomics effort
• We would like the whole community to be involved
  in building.
• Openmind collects NL knowledge over the web.

10
Existing effort SUMO and MILO

• http//www.ontologyportal.org/
• SUMO and MILO are freely available
• SUMO
• http//cvs.sourceforge.net/viewcvs.py/checkout/s
  igmakee/KBs/Merge.kif?rev1.3
• MILO
• http//cvs.sourceforge.net/viewcvs.py/checkout/s
  igmakee/KBs/Mid-level-ontology.kif?rev1.2

11
SUMO

• SUMO (Suggested Upper Merged Ontology)
• Based on first-order logic.
• It incorporates
• elements of John Sowa's upper ontology
• Russell and Norvig's ontology
• PSL (Process Specification Language),
• Casati and Varzi's theory of holes,
• Allen's temporal axioms, etc.
• It has a nice browsing and editing tools, and
• Inference and Ontology management system
• http//sigmakee.sourceforge.net/

12
MILO (MId-Level Ontology)

• Aim is to be a bridge between the abstract
  content of the SUMO and the rich detail of the
  various domain ontologies.
• In progress, incomplete.
• Contains a Description Logic Knowledge base
• Class-subclass
• Class-instances
• Relations

13
Going beyond SUMO and MILO?

• Why?
• Both SUMO and MILO are based on first-order
  logic.
• Need ways to express defaults and exceptions,
• need ways to express problem solving queries,
  such as planning, diagnosis, etc.

14
Recall What do we need?

• A large body of Knowledge modules possibly
  grouped in packages
• Common sense modules
• Domain specific modules
• High level modules actions, time, space, etc.
• Methodology to facilitate building modules
• Inheritance, encapsulation, modeling languages,
  etc.
• Interface mechanisms similar (in functionality)
  to interface mechanisms in Java, C etc.

15
Coupling modules and inference mechanism

• AnsProlog versus ASP
• AnsProlog -- Programming in logic with answer
  sets
• ASP seems to be focused on the generate and
  test problem solving
• Need modules of various kinds
• Is ancestor(john,mary)? (Prolog
  style)
• Find a plan (ASP style)
• Find a schedule (CLP)
• Different kinds of modules may need different
  inference mechanisms

16
Next Steps, challenges

• Lets look at the AAAI06 Spring Symposium CFP.

17
AAAI06 Spring symposium

• Title Formalizing and Compiling Background
  Knowledge and its applications to Knowledge
  Representation and Question Answering.
• Organizing Committee
• Chitta Baral (chitta_at_asu.edu)
• Alfredo Gabaldon (alfredo.gabaldon_at_nicta.com.au)
• Michael Gelfond (mgelfond_at_cs.ttu.edu)
• Joohyung Lee (appsmurf_at_cs.utexas.edu)
• Vladimir Lifschitz (vl_at_cs.utexas.edu)
• Steve Maiorano (stevemai_at_mac.com)
• Sheila McIlraith (sheila_at_cs.toronto.edu)
• Leora Morgenstern (leora_at_steam.stanford.edu)

18
CFP Requests contributions that are

• A formalizations (knowledge modules) of
  background knowledge in specific domains as well
  as,
• B papers addressing general challenges such as
  formalizing background knowledge for use by
  multiple users on multiple reasoning tasks.
• Interface issues, reuse, etc.

19
A Knowledge module papers

• No restriction on the domain to be formalized or
  on the level of specificity
• Suggested common format
• A knowledge base (KB) written in English.
• Examples of informal consequences of KB,
  preferably accompanied by some explanations,
  including defaults and other commonsense
  knowledge not directly mentioned in KB but needed
  to produce the desired consequence.

20
A Knowledge module papers (cont.)

• Information about which logic/language is used in
  formalizing it.
• (Syntax, semantics, and where the reasoning
  system is available.)
• The formalization
• Short description on how the formalization can be
  tested using the reasoning system.

21
Existing knowledge encoded in AnsProlog

• Small AnsProlog programs (not quite modules
  dont have modular interface)
• Knowledge Representation, Reasoning and
  Declarative Problem Solving. Baral
• Various surveys Niemela et al. Gelfond and
  Leone. Etc.
• Larger programs
• RCS-USA Advisor (http//www.krlab.cs.ttu.edu///Sof
  tware/)
• www.baral.us/bookone/
• Vladimir is collecting a list of ASP
  applications.

22
Further ideas for submissions of type A.

• At various abstractions
• Actions, time, space, etc.
• Various domains
• Travel, terrorism, etc.
• Further collections and catalogues of existing
  encoded knowledge.

23
B Interface and Engineering issues

• How to call a module from another module
  interface syntax and semantics
• Object oriented issues
• Encapsulation
• Classes, sub-classes, Inheritance
• Polymorphism
• Modeling language

24
Some initial steps on Interface issues

• Towards an Integration of Answer Set and
  Constraint Solving. Baselice, Bonatti and
  Gelfond. ICLP05
• A language for modular ASP. Tari, Baral, Anwar.
  ASP05.
• Enhancing ASP with templates. Ianni et al.
  NMR2004.
• Personal communication. Lifschitz.
• F-logic papers. Kifer et al.

25
Challenges vis-à-vis C and Java libraries

• Number of modules could be much larger and much
  varied than classes and methods in Java libraries
  
• Multiple AnsProlog sub-languages, each with a
  different reasoning mechanism
• Various sources of knowledge some would be
  learned
• Initially a smaller number of developers
• Language is still evolving (core is there)

26
More info on the symposium

• Symposium Dates
• March 27-29 2006.
• AAAI site
• http//www.aaai.org/Symposia/Spring/2006/ssspartic
  ipation-06.pdf
• Symposium cite
• http//www.public.asu.edu/cbaral/aaai06-ss/
• Deadlines
• Submission October 7, 2005 (extended to October
  21st)
• Response November 4, 2005
• Camera ready due at AAAI January 27, 2006
• Symposium date March 27-29 2006.

27
Thank You