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The Independent Choice Logic for modeling multiple agents under uncertainty. David Poole Http://www.cs.ubc.ca/spider/poole Presented by Mei Huang Mar. 18,2005. Outline. Knowledge Representation ICL Overview ICL Semantics ICL Influence Discussion. Outline. Knowledge Representation - PowerPoint PPT Presentation
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The Independent Choice Logic for modeling multiple agents
under uncertainty
David Poole
Http://www.cs.ubc.ca/spider/poole
Presented by Mei Huang
Mar. 18,2005
Outline
Knowledge RepresentationICL OverviewICL SemanticsICL InfluenceDiscussion
Outline
Knowledge Representation ICL OverviewICL OverviewICL SemanticsICL InfluenceDiscussion
“a bridge between logical representation and belief networks”
Q?
Discussion
What do you think of the author’s claim that using disjunction to handle uncertainty is a stupid thing?
From the view point of representation, disjunction is not that bad, at least, it provides compact representations than ICL. E.g, “ea1v …v an” in ICL needs n expressions.
Outline
Knowledge RepresentationICL Overview ICL SemanticsICL SemanticsICL InfluenceDiscussion
Note: each item in F, i.e, each rules has an associated probability. E.g, for the first rule, the probability is P(f | c1, b1). This probability is different from the probability of a possible world.
Q?
Discussion
How to cast the student-take-course domain problem into ICL?
Choice Space C={{L1,L2,L3},{High,Normal,Easy}}
Facts F={Grade=A IQ=L3 ^ Difficulty=Easy;
Grade=B IQ=L2 ^ Difficulty=High; ……}
Give P0(L1), P0(L2), P0(L3), P0(High), P0(Normal),
P0(Easy)
Outline
Knowledge RepresentationICL OverviewICL Semantics ICL InfluenceICL InfluenceDiscussion
Q?
Discussion
Why it looks so straight forward to map a decision tree to the rules of ICL?
The logical part of ICL focuses on attributes’ values, not attributes. ICL’s Fact set F interprets CPDs of BLP or LoPRM.
Q?
How to translate this BN into ICL?
It is better to redraw the graph as 88 belief networks as follows:
……
Because ICL’s rules are defined on the value level.
Discussion
Burglary earthQuake
Alarm
B=true Q=true
A=true
are mutually exclusive
Outline
Knowledge RepresentationICL OverviewICL SemanticsICL InfluenceDiscussionDiscussion
Discussion
In the diagram in slide15, why the arrows are uni-directional? Can they be made bi-directional?
What can ICL buy us? I.e, is this explicit bridge between logic and decision theory necessary or is the gap between the two enlarged imaginarily by the author? (when we deal with decision projects, logic is usually embodied implicitly in the program)