CSE655: Probabilistic Reasoning

Assignment # 4

Date: December 4, 2009

Due Date: December 11, 2009

Consider this Bayesian Network.

  1. Problem 1
    • Using Logic Sampling and Likelihood Weighting, generate 200 samples and compute P(A | B, ~E), P(C | B, ~E) and P(D | B, ~E).
    • Repeat the exercise 5 times with unique random variables.
    • Compute the average of P(A | B, ~E), P(C | B, ~E) and P(D | B, ~E) based on the 5 estimates computed in the above steps (for both logic sampling and likelihood weighting). Compare this average with the exact results produced by GeNIe.
  2. Repeat Problem 1 with sample sizes of 400, 600, 800 and 1000.
  3. Draw a graph where the x-axis shows the sample size while the y-axis shows the difference between the average probabilities (produced by both sampling techniques) and the exact probabilities produced by GeNIe.