CS 6601 Project 4
Bayesian Networks
Due: Dec. 3, 2004

The goal of this project is to give you experience using bayesian networks. You are asked to design a simple expert system in the domain of your choice and implement it using existing software. This project does not involve any programming.

Assignment

Choose an area you are very familiar with. Some examples include predicting the weather, troubleshooting a car, diagnoising a cold, predicting your grade in 6601, etc... These examples are only meant to show you that the area does not have to be a technical one. After you choose an area, design a simple Bayesian network with 8 to 15 nodes. Make sure that your network has an interesting topology. (eg. Do NOT design a flat or linear network).

Implement your network using GeNIe, a development environment for building decision-theoretic models. Get familiar with the basic functionalities of GeNIe (namely building a network with chance nodes and relations, setting evidence, and querying the network) and implement your network. GeNIe runs on Windows. To use it, you will need to download it from http://www2.sis.pitt.edu/~genie. The software has comprehensive online documentation.

Perform some queries with your expert system. For each query, set evidence on some nodes and read off the values from other nodes.

Familiarize yourself with other features of GeNIe that we did not cover in class such as influence diagrams. Show how they can be used for planning, that is action selection. Provide a brief, concrete example of such an application.

Deliverables

Submit the following in a hardcopy in class:
  1. A screen shot of your Bayes Net
  2. A concise description of your Bayes net. i.e. the overall purpose of your expert system and the meaning of the nodes
  3. A description of your queries (at least two): The evidence used and the node(s) queried as well as the posteriori probabilities at these queried nodes. Also, explain the results you obtain. Your work should demonstrate that your network indeed encodes your expertise effectively.
  4. A short writeup of using other features of GeNIe and using action selection (part 4 above)
Nothing else is required to be handed in.

Grading will be based on your production of an interesting (non-trivial) network, demonstration of some interesting queries, and most importantly your analysis and exploration of other features. The straightforward portions of the assignment should be _very_ easy to produce, and they will receive less weight than the more thought/insight demanding portion. The writeup does not need to be extremely long, but it should demonstrate that you have developed some insights.

Additional Notes

GeNIe has been known to crash (anecdotally) so save often.