Machine Learning (W4771)

Homework 3: Neural Networks

Due Date: Class time, Part I:Thursday February 24, Part II: Thursday March 2. The Part I hand-in is done simply by e-mailing to Dave (devans@cs.columbia.edu), in text, enough to show you have done it -- it won't be graded until after handing in the complete hardcopy submission for both parts (together, on the Part II deadline).

Reading: Chapter 4 of "Machine Learning" by Tom M. Mitchell. Note, Sections 4.5.3 and 4.8 are optional. However, section 4.8 may provide ideas for the Part II of this assignment.

Your assignment: Follow the instructions for Mitchell and Blum's "Neural Networks and face images" assignment. The first level of detail for this project is described in section 4.7 of Mitchell's text. The remaining details for the NN implementation and assignment are in hw96.ps, attached if you got this handout in class. You are provided with a NN implementation in C, which you will have to modify a little. Note that this assignment description says "Homework 5", but this is actually your third assignment, and also note the above due date, in contrast to that in the description.

Like decision trees, this assignment has two parts, the second of which is open-ended. For this assignment, we strongly recommend that you team up for the second part. For the second part you will optionally make a brief presentation in class, and will hand in a write-up.

Part I:

Changes from the assignment description file:

For Part I you are to hand in answers to the questions listed among the 13 steps described in the assignment.

Part II:

For the open-ended portion of the assignment, we strongly recommend you team up with one or two other people. This way, you can build on each other's ideas, share the implementation and write-up responsibilities, and have more fun. For this portion, you hand in one write-up for your group.

Since you do not have to write the implementation from scratch, emphasis is weighted more on Part II of this assignment than it was for the decision tree assignment. However, do be careful again to keep your experiments very reasonable in terms of effort -- there are still two more projects after this one. If you have "big ideas", they may best wait until the final project, which is, in principle, completely open-ended (i.e., can use NNs, decision trees, GAs, anything).

Please choose something that you find interesting. Your choice should be motivated, not just random. You should be able to explain why your experiment was an interesting thing to try out.

In addition to the suggestions listed in the assignment description file, other possibilities include:

Deliverables for Part II:

email: evs at cs dot columbia dot edu