Using Misunderstanding and Discussion in Dialog as a Knowledge Acquisition or Enhancement Procecss - Distributed Artificial Intelligence, Agent Technology, and Collaborative Applications - page 82

Conflict Management Strategies Through Discussion: KB Consistency Preservation Common
Goal. We have studied several types of conflict, those related to implications as well as those related
to facts.
Implication conflicts. These conflicts typically take place when the 'student' has a formula ( P → Q )
and attempts to learn a formula ( P →¬( Q )). The solution, for the 'student', is to remove ( P → Q ) from its
KB and add ( P →¬( Q )). It acts so because this is 'teacher”s knowledge (thus true) and so it gets the
upper hand on the 'student' one (first axiom). However, the conflict could be hidden if the 'student' has
the next formulas: ( P 1 → P 2 ), ( P 2 → P 3 ), ..., ( P n −1 → P n ) and attempts to learn ( P 1 → P n ): The 'student' has an
equivalent to the formula 1 n . Instead of using a baseline solution consisting in removing all the series of
implications, we opted for a more flexible one which attempts to look for a wrong implication and only
removes this very one. Indeed, deleting one implication is sufficient to solve the conflict. The 'student'
will then attempt to validate each implication with the 'teacher' through an ' askfor - information ' request.
As soon as a wrong implication is found, the 'student' removes it and safely adds the new one. However,
if none of the implications is neither validated nor rejected by the 'teacher', the 'student' will be forced
to remove all the series before adding the new one to be sure to end up the conflict.
We present now an example of a solvable conflict, inspired from the following sophism:
All that is cheap is rare.
All that is rare is expensive.
Therefore, all that is cheap is expensive.
The dialog of the Figure 5 is an example of dialog our agents should use when facing such a conflict.
The KB evolution can be followed, step by step, in the Figure 6.
Figure 5. Dialogue using a discussion strategy for implication conflict resolution
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The 'student' owns the following knowledge (Step 1):
cheap(x) → rare(x)
rare(x) → expensive(x)
— 'Teacher' - give - knowledge ( cheap ( x )→¬( expensive ( x )))
“All that is cheap is not expensive.”
The 'student's' adds this knowledge to its KB (Step 2), however the implication comes into contradiction with the
student's base.
The 'student' will then try to locate the wrong implication(s).
— 'Student' - askfor - information ( cheap ( x )→ rare ( x ))
“Does all that is cheap is rare? ”
— 'Teacher' - give - information ( t rue )
“Yes”
— 'Student' - askfor - information ( rare ( x )→ expensive ( x ))
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