Final exam marks..

[Subbarao Kambhampati <rao@asu.edu>]

Final has been graded. Before witnessing the bloodbath, let us 
pause--in the true Bhagavadgita fashion--
and take stock of the big answers ;-)

Here are some general observations:

1. Many people messed up the bomb in the toilet problem.
Here is one complete answer.

1. B(p1,S0) V B(p2,S0)
2. forall s, p  B(p,s) => sf(Result(d(p),s))
3. ?sf(s)

1 is already in the clausal form. 2 becomes   ~B(p,s) V sf(Result(d(p),s))
3, after negation becomes forall s ~sf(s)  which in clausal form is ~sf(s)

You can resolve 3 with 2, and then resolve ~B(p,s) twice with 1 to 
get an empty clause

The proof doesn;t give you a plan as it is existential proof.

Backward chaining won't work because the first clause is non-horn!

2. for part two of the flu epidemic question, many people missed the point that
the CPTs already take care of the ignorance and lazyness..

3. The likelihood of Flu in the enumeration question works out to be 
about ~0.733

4. In the likelihood weighting question, you ignore the last few 
samples since you
have to clamp RN and BA to "False"

5. The answer to how likely is flu on the first day given the 
evidence of the kit on the second
day turns out to be  ~0.824 [You guys could have used the project 3 
applet to check your answers
before submitting ;-)]

6. for the third part of the DBN question, the best way to argue with 
your friend is to
point out that belief revision can happen in diagnostic as well as 
causal direction.


7. For the Neuman's party, the size of the hypothesis space is 
2^(2^3)=256 (where
3 is the number of features of the problem)

8. For the same question, some people used their commonsense rather 
than calculations

9. The answers to deep thoughts section made for interesting reading. 
Seemed like some people really did
get something out of the course--and that is as apt a gift for the 
winter solstice as any..

cheers
Rao

------
(*) Bhagavadgita is considered the Cliff's notes essence of Hindu 
philosophy--and it is
a discourse on good and bad between Krishna and Arjuna--two 
characters in the Indian
epic Mahabharata--at the outset of the big war--with two opposing 
armies pitched and ready to
go at each other. Imagine, if you will, a philosophical discussion 
between G.W. and Saddam in the deserts
of arabia, with the republican guard and marines ready to go at each 
other once they stop talking..