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Talk at ECSQARU 2009
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University of BresciaDipartimento di Elettronica per l'Automazione
Knowledge Engineering and Human-Computer Interaction Research Group
© 2009 Federico Cerutti <[email protected]>
Encompassing Attacks to Encompassing Attacks to Attacks in Abstract Attacks in Abstract
Argumentation FrameworksArgumentation Frameworks
Pietro Baroni, Federico Cerutti, Massimiliano Giacomin and Giovanni GuidaPietro Baroni, Federico Cerutti, Massimiliano Giacomin and Giovanni Guida
Slide 2 © 2009 Federico Cerutti <[email protected]>
Summary
Introduction by example Formalization Relationship with Dung's Argumentation Framework Comparison with other approaches Conclusion and future works
© 2009 Federico Cerutti <[email protected]>
Introduction by exampleIntroduction by example➢ Formalization
➢ Relationship with Dung's Argumentation Framework➢ Comparison with other approaches
➢ Conclusion and future works
Slide 4 © 2009 Federico Cerutti <[email protected]>
Example (1)
Simple decision support problem Bob's holidays plan Two possible choices:
Gstaad Cuba
Preferences among the possible choices Exception to the preference's general rule
Slide 5 © 2009 Federico Cerutti <[email protected]>
Example (2)
There is a last minute offer for Gstaad →
I should go to Gstaad
GG
If I go to Cuba, I can notgo to Gstaad
There is a last minute offer for Cuba →
I should go to Cuba
CC
Slide 6 © 2009 Federico Cerutti <[email protected]>
Example (3)
GG
PP
CC
When it is possible, I preferto go to a ski resort
According to this preference, the possible choice for Cuba can
not attack the one for Gstaad
Slide 7 © 2009 Federico Cerutti <[email protected]>
Example (4)
GG
PP
CC
The preference aboutskiing does not apply
in the current situation
NN
Since there were no snowfalls inGstaad since a month, it is notpossible to go to ski in Gstaad.
Slide 8 © 2009 Federico Cerutti <[email protected]>
Example (5)
GG
PP
CC
AA NN
It is possible to ski in Gstaadthanks to artificial snow
© 2009 Federico Cerutti <[email protected]>
FormalizationFormalization➢ Introduction by example
➢ Relationship with Dung's Argumentation Framework➢ Comparison with other approaches
➢ Conclusion and future works
Slide 10 © 2009 Federico Cerutti <[email protected]>
Argumentation Framework withRecoursive Attacks (AFRA)
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Formalization of the example (1)
GG
PP
CC
AA NN
d
a
b
g
e
Slide 13 © 2009 Federico Cerutti <[email protected]>
Formalization of the example (2)
GG
PP
CC
AA NN
d
a
b
g
e
Slide 16 © 2009 Federico Cerutti <[email protected]>
GG
PP
CC
AA NN
d
a
b
g
e
Formalization of the example (3)
© 2009 Federico Cerutti <[email protected]>
Relationship with Dung's Relationship with Dung's Argumentation FrameworkArgumentation Framework
➢ Introduction by example➢ Formalization
➢ Comparison with other approaches➢ Conclusion and future works
Slide 18 © 2009 Federico Cerutti <[email protected]>
Correspondence between AFRA and AF (1)
AA
BB
aa
bb
CCAA
BBbb
aa
CC
gg
gg
Slide 19 © 2009 Federico Cerutti <[email protected]>
Correspondence in the example
GG
ee
PP
CC
AA NN
gg
dd
aa
bb
GG
PP
CC
AA NN
d
a
b
g
e
Slide 21 © 2009 Federico Cerutti <[email protected]>
GG
ee
PP
CC
AA NN
gg
dd
aa
bb
Correspondence in the example:The Preferred Extension
GG
PP
CC
AA NN
d
a
b
g
e
© 2009 Federico Cerutti <[email protected]>
Comparison with other Comparison with other approachesapproaches
➢ Introduction by example➢ Formalization
➢ Relationship with Dung's Argumentation Framework
➢ Conclusion and future works
Slide 23 © 2009 Federico Cerutti <[email protected]>
Argumentation attack model
Modelling the strength of nodes and attacks with propagation
Argumentation attack model [Barringer et al, 2005] Recursive definition of “torpedoes”, or attacks,
similarly as AFRA attacks Focus on attack network and its numerical valuation Dung style semantics issues not considered
Slide 24 © 2009 Federico Cerutti <[email protected]>
The EAF formalism
Reasoning about preferences/values can be formalized through attacks to attacks
Extended Argumentation Framework [Modgil, 2007;2009]
Specific assumptions: A limited level of recursion A constraint on some attacks to be symmetric (when the
involved arguments represent conflicting preferences)
In the paper we have considered a possible extension of EAF aimed at overcoming these restrictions
Slide 25 © 2009 Federico Cerutti <[email protected]>
Higher-order AF
Reasoning about coalitions Model of attacks to attacks as an instance of Dung's
Argumentation Framework Proposal of a “second order argumentation
framework” with some constraints like EAF Proposal of a “higher order argumentation
framework” without such constraints [Boella et al, 2009]
© 2009 Federico Cerutti <[email protected]>
Conclusion and future Conclusion and future worksworks
➢ Introduction by example➢ Formalization
➢ Relationship with Dung's Argumentation Framework➢ Comparison with other approaches
Slide 27 © 2009 Federico Cerutti <[email protected]>
Conclusion and future works
Preliminary investigation about AFRA Generalization of Dung's Argumentation Framework Attacks to attacks recursively encompassed without
restriction Focus on decision support context Future works:
Enlarging the theoretical bases of AFRA Investigating the definition of argumentation semantics in
this context
