| Input: , the DAG of the KBN; |
| : the evidence nodes in (the new ad’s keywords); |
| : the non-evidence nodes in (all keywords except for the new ad’s keywords); |
| : the set of values of the evidence (set 1 as the value); |
| : the query variable (the keyword will be inferred); |
| : the total times of sampling. |
| Output: The estimates of |
| Variables: |
| : the set of the values of the non-evidence; |
| ; |
| : the current state of the KBN; |
| : the number of the samples when the value of is 1 |
| Steps: |
| (1) Initialization: |
| values of in Z |
| |
| |
| (2) For to Do |
| (i) Compute the probabilities of the selected variables based on the state , |
| Randomly select one non-evidence variable from : |
| , where is the set of the values in the |
| Markov chain of in the current state |
| (ii) Generate a random number and we determine the value of : |
| (5) |
| |
| (iii) Count |
| If Then |
| End For |
| (3) Estimate |
| |
