10 Mar 2004
CS 3243 - Uncertainty
19
Independence
nA and B are
independent iff
P(A|B) = P(A) or P(B|A) = P(B) or P(A, B) = P(A) P(B)
P(Toothache, Catch,
Cavity, Weather)
= P(Toothache, Catch,
Cavity) P(Weather)
n32 entries reduced to 12 (8+4);
for n independent biased coins, O(2n) →O(n)
for n independent biased coins, O(2n) →O(n)
nAbsolute independence powerful but rare
nDentistry is a large field with hundreds of variables,
none of which are independent.
What to do?
