Ch. 15

1
Ch. 15 Probabilistic Reasoning Over Time

• Supplemental slides for CSE 327
• Prof. Jeff Heflin

2
Umbrella World Example
P(R0)lt0.5,0.5gt
Rt-1 P(Rt)
T 0.7
F 0.3
Raint-1
Raint
Raint1
Rt P(Ut)
T 0.9
F 0.2
Umbrellat1
Umbrellat-1
Umbrellat
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Filtering (Umbrella World)

• On day 1, if U1true
• prediction from t0 to t1
• lt0.7,0.3gt ? 0.5 lt0.3,0.7gt ? 0.5
• lt0.5,0.5gt
• update with evidence for t1
• ?lt0.9,0.2gtlt0.5,0.5gt
• ?lt0.45,0.1gt
• ? lt0.818,0.182gt

• On day 2, if U2true
• prediction from t1 to t2
• lt0.7,0.3gt ? 0.818 lt0.3,0.7gt ? 0.182
• ? lt0.627,0.373gt
• updating with evidence for t2
• ?lt0.9,0.2gtlt0.627,0.373gt
• ?lt0.565,0.075gt
• ? lt0.883,0.117gt