CAMBRIDGE, UK, 11 DEC 2008
Redux exp: An
Open-source Justification-
based Explanation Support Server
Thomas Roth-Berghofer & Florian Mittag
Senior researcher, trb@dfki.de
German Research Centre for Artificial Intelligence DFKI GmbH
Samstag, 18. Juli 2009

What are
explanations?
Samstag, 18. Juli 2009

What are
explanations?
Samstag, 18. Juli 2009

What are
explanations?
Explanations
are answers to
questions.
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Explanations are a kind
of information.
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Concepts connected with the
notion of information
THE COACH TO STANSTED
AIRPORT LEAVES
CAMBRIDGE AT 17:30 H.
Samstag, 18. Juli 2009

Concepts connected with the
notion of information
• Truth
THE COACH TO STANSTED
AIRPORT LEAVES
CAMBRIDGE AT 17:30 H.
Samstag, 18. Juli 2009

Concepts connected with the
notion of information
• Truth
• Understanding
THE COACH TO STANSTED
AIRPORT LEAVES
CAMBRIDGE AT 17:30 H.
Samstag, 18. Juli 2009

Concepts connected with the
notion of information
• Truth
• Understanding
THE COACH TO STANSTED
AIRPORT LEAVES • Utility
CAMBRIDGE AT 17:30 H.
Samstag, 18. Juli 2009

Concepts connected with the
notion of information
• Truth
• Understanding
THE COACH TO STANSTED
AIRPORT LEAVES • Utility
CAMBRIDGE AT 17:30 H. • Storage and
retrieval
Samstag, 18. Juli 2009

Concepts connected with the
notion of information
• Truth
• Understanding
THE COACH TO STANSTED
AIRPORT LEAVES • Utility
CAMBRIDGE AT 17:30 H. • Storage and
retrieval
• Information
generation
Samstag, 18. Juli 2009

Concepts connected with the
notion of information
• Truth
• Understanding
THE COACH TO STANSTED
AIRPORT LEAVES • Utility
CAMBRIDGE AT 17:30 H. • Storage and
retrieval
• Information
generation
Samstag, 18. Juli 2009

Basic explanation scenario
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Knowledge sources
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Problem solving
knowledge
Knowledge sources
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Explanation
knowledge
Problem solving
knowledge
Knowledge sources
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Explanation
knowledge
Problem solving
knowledge
Knowledge sources
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Example:
course assignment
• Professors Descartes and Kant
• Descartes more senior than Kant
René Descartes
• Heuristics: 1596–1650
• Try to assign a course to the professor who wants
to teach that course.
• Assign courses to senior professors first.
• Preferences:
• Descartes wants to teach course PHL305.
• Kant also wants to teach course PHL305.
Immanuel Kant
• Kant would also teach course PHL380. 1724–1804
Samstag, 18. Juli 2009

Example:
course assignment
• Decisions: René Descartes
1596–1650
• Descartes will teach PHL305.
• Kant will teach PHL380.
• What happens if Descartes could
not teach PHL305?
Immanuel Kant
1724–1804
Samstag, 18. Juli 2009

Justification-based Truth
Maintenance Systems
• Network of nodes and justifications,
which are labelled IN or OUT:
• Node is labelled IN <=> at least one of its supporting
justifications is labelled IN
• Justification is labelled IN <=> each element in its IN-list
is labelled IN and each element in its OUT-list i labelled
OUT
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REDUX
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REDUX
G1
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REDUX
G1
O1
O2
…
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REDUX
G1
Conflict
set
O1
O2
…
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REDUX
G1
Conflict
set
O1
Decision
O2
…
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REDUX
G1
Conflict
set
O1
Decision
O2
…
Reduction
…
G2 Gn
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REDUX
G1
Conflict
set
O1
Decision
O2
…
Reduction
…
G2 Gn A1, A2, …
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REDUX : Goal reduction
G1
Conflict
set
O1
Decision
O2
…
Reduction
…
G2 Gn A1, A2, …
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Redux exp Architecture
• Provenance
• who decided
• and when
• Persistence
• serialisation of network
into RDF/XML
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Example:
course assignment
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Example:
course assignment
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Example:
course assignment
Samstag, 18. Juli 2009

Example:
course assignment
Samstag, 18. Juli 2009

Example:
course assignment
• Kant enquires about his assignment:
Samstag, 18. Juli 2009

Example:
course assignment
• Kant enquires about his assignment:
FOR EACH assignment IN redux.getAllAssignments() {
IF assignment.getName() == "Kant teaches PHL305"
RETURN assignment;
}
IF assignment != null
PRINT assignment.isValid();
Samstag, 18. Juli 2009

Example:
course assignment
• Kant: “Why didn’t I get to teach PHL305?”
decisions[] = redux.getDecisionsForAssignment(assignment);
Samstag, 18. Juli 2009

Example:
course assignment
• Kant: “Why didn’t I get to teach PHL305?”
decisions[] = redux.getDecisionsForAssignment(assignment);
rejections[] = decisions[0].getRejectionReasons();
Samstag, 18. Juli 2009

Example:
course assignment
• Kant: “Why didn’t I get to teach PHL305?”
decisions[] = redux.getDecisionsForAssignment(assignment);
rejections[] = decisions[0].getRejectionReasons();
ReduxReason rejection = rejections[0];
PRINT "Assignments: ";
FOR EACH a IN rejection.getConditionAssignments {
PRINT a.getName() + " by " + a.getCreator();
}
PRINT "Facts: ";
FOR EACH f IN rejection.getConditionFacts {
PRINT f.getName() + " by " + f.getCreator();
}
PRINT "Rejected decisions: ";
FOR EACH d IN rejection.getConditionDecisions {
PRINT d.getName() + " by " + d.getCreator();
}
Samstag, 18. Juli 2009

Example:
course assignment
• Output:
Assignments: "Descartes teaches PHL305" by ’Administrator’
Facts: "At most one teacher per course" by ’Administrator’
Rejected decisions: none
Samstag, 18. Juli 2009

Example:
course assignment
• Output:
Assignments: "Descartes teaches PHL305" by ’Administrator’
Facts: "At most one teacher per course" by ’Administrator’
Rejected decisions: none
Note:
• Reduxexp does not generate
explanations, it supports the
process by providing the
necessary information
Samstag, 18. Juli 2009

Example:
course assignment
• Output:
Assignments: "Descartes teaches PHL305" by ’Administrator’
Facts: "At most one teacher per course" by ’Administrator’
Rejected decisions: none
Note:
• Reduxexp does not generate
explanations, it supports the
process by providing the
necessary information
• Client application supplies
semantics.
Samstag, 18. Juli 2009

Take home messages
Samstag, 18. Juli 2009

Take home messages
• Explanations are important for
increasing the trustworthiness of
decision support systems.
Samstag, 18. Juli 2009

Take home messages
• Explanations are important for Explainer
increasing the trustworthiness of
User
decision support systems.
Originator
• Explanations are part of
communication scenario.
Samstag, 18. Juli 2009

Take home messages
• Explanations are important for Explainer
increasing the trustworthiness of
User
decision support systems.
Originator
• Explanations are part of
communication scenario.
• Explanation provision is only possible
if the respective information is
available.
Samstag, 18. Juli 2009

Take home messages
• Explanations are important for Explainer
increasing the trustworthiness of
User
decision support systems.
Originator
• Explanations are part of
communication scenario.
• Explanation provision is only possible
if the respective information is
available.
• Reduxexp is a server for logging /
recording decisions.
MORE INFORMATION AND DOWNLOAD:
HTTP://REDUXEXP.OPENDFKI.DE
Samstag, 18. Juli 2009

Thank you!
CAMBRIDGE, UK, 11 DEC 2008
Redux exp: An
Open-source Justification-
based Explanation Support Server
Thomas Roth-Berghofer & Florian Mittag
Senior researcher, trb@dfki.de
German Research Centre for Artificial Intelligence DFKI GmbH
Samstag, 18. Juli 2009

Invitation to participate
• ExaCt mailing list:
http://groups.yahoo.com/group/explanation-research/
• ExaCt 2009 @ IJCAI 2009
http://exact2009.workshop.hm
Samstag, 18. Juli 2009

Publications of ExaCt
research group
2008 2007 (contd.)
[Bahls, 2008] Bahls, D. (2008). Explanation support for the case-based [Roth-Berghofer et al., 2007] Roth-Berghofer, T. R., Schulz, S., and Leake,
reasoning tool myCBR. Project thesis, University of Kaiserslautern. D. B., editors (2007). Proceedings of the AAAI-07 workshop on
[Forcher et al., 2008] Forcher, B., Adrian, B., and Roth-Berghofer, T. (2008). Explanation-aware Computing ExaCt2007. AAAI Press. Technical Report
Explanations in the information extraction system iDocument. Künstliche WS-07-06.
Intelligenz, 22(2). 2006
[Mittag, 2008] Mittag, F. (2008). ReduxExp: A justification-based [Richter et al., 2006] Richter, M. M., Roth-Berghofer, T., and Schulz, S.,
explanation-support server. Project thesis, University of Kaiserslautern. editors (2006). Explanation-aware Computing, volume 25. SAP - Slovak
[Roth-Berghofer and Bahls, 2008] Roth-Berghofer, T. R. and Bahls, D. Academic Press Ltd., Bratislava.
(2008). Code tagging and retrieval with myCBR. In Petridis, M., Coenen, F., 2005
and Bramer, M., editors, Research and Development in Intelligent Systems [Roth-Berghofer et al., 2005a] Roth-Berghofer, T., Cassens, J., and Sørmo,
XXV, London, UK. Springer Verlag. F. (2005a). Goals and kinds of explanations in case-based reasoning. In
[Roth-Berghofer and Mittag, 2008] Roth-Berghofer, T. R. and Mittag, F. Althoff, K.-D., Dengel, A., Bergmann, R., Nick, M., and Roth-Berghofer, T.,
(2008). ReduxExp: A justification-based explanation-support server. editors, WM 2005: Professional Knowledge Management, pages 264–268,
Proceedings of AI-2008. the twenty-eighth SGAI international conference Kaiserslautern, Germany. DFKI GmbH.
on artificial intelligence. In Petridis, M., Coenen, F., and Bramer, M., editors,
[Roth-Berghofer and Cassens, 2005] Roth-Berghofer, T. R. and Cassens, J.
Research and Development in Intelligent Systems XXV, London, UK.
(2005). Mapping goals and kinds of explanations to the knowledge
Springer Verlag.
containers of case-based reasoning systems. In Muñoz-Avila, H. and Ricci,
[Roth-Berghofer and Richter, 2008a] Roth-Berghofer, T. R. and Richter, M. F., editors, Case-Based Reasoning Research and Developmen, pages 451–
M., editors (2008a). Künstliche Intelligenz—Topic: Explanation, volume 22, 464, Heidelberg. Springer Verlag.
Bremen. BöttcherIT Verlag.
[Roth-Berghofer et al., 2005b] Roth-Berghofer, T. R., Schulz, S., and
[Roth-Berghofer and Richter, 2008b] Roth-Berghofer, T. R. and Richter, M. Woody, A., editors (2005b). Proceedings of the AAAI Fal l Symposium on
M. (2008b). On explanation. Künstliche Intelligenz, 22(2):5–7. Explanation-aware Computing ExaCt2005. AAAI Press. Technical Report
2007 FS-05-04.
[Bahls and Roth-Berghofer, 2007] Bahls, D. and Roth-Berghofer, T. (2007). 2004
Explanation support for the case-based reasoning tool myCBR. In [Roth-Berghofer, 2004] Roth-Berghofer, T. R. (2004). Explanations and
Proceedings of the Twenty-Second AAAI Conference on Artificial Case-Based Reasoning: Foundational issues. In Funk, P. and González-
Intelligence. July 22–26, 2007, Vancouver, British Columbia, Canada., Calero, P. A., editors, Advances in Case-Based Reasoning, pages 389–403.
pages 1844–1845. The AAAI Press, Menlo Park, California. Springer-Verlag.
[Eppert, 2007] Eppert, M. (2007). Generating provenance explanations for
the gnowsis rebirth machine - a first pass. Pro ject thesis, University of
Kaiserslautern.
Samstag, 18. Juli 2009