# Using Decision Trees

Using Decision Trees

Using Decision Trees-To receive full credit for discussion participation, you should post a message during the first three days of the module. The Week 1 topic requires nothing more than some thought and reflection, while the Week 2 topic requires specific knowledge of the module’s contents. For full credit, you should respond to both topics. We suggest you do the Week 1 topic first, but please feel free to respond to either topic, at any time.

Week 1 Topic: What to do, what to do???

Metaphorically, the road through life has many intersections; sometimes a T-intersection (go left or right), sometimes a crossroads (go left, right, or straight ahead), and sometimes a roundabout with many alternatives. Each alternative leads to several possible outcomes, with each outcome having a probability that ranges from highly unlikely to almost certain. Choosing the right outcome is sometimes complicated, and it would be nice to have a tool to help us make the choice.

Describe and discuss a situation in which you had to choose among several alternative courses of action. What were the possible outcomes of each alternative? How did you choose an alternative?

Week 2 Topic: Sometimes decision trees don’t grow.

Decision trees are attractive. They offer a straightforward way of writing down the various available alternatives  and choosing among them. But here are some questions that always need answering.

1. Can the decision really be reduced to a set of discrete alternatives? Are there some factors that can’t be listed and quantified, such as beauty and morality?
2. Where do the alternatives come from? Are they exhaustive? That is, have we discovered and listed all of them? Do they reflect reality or only the biases and preconceptions of the decision maker?
3. How confident are we in the outcome values, aka the payoffs? Are they time-sensitive?
4. How confident are we in the probabilities attached to the outcomes? Where on Earth did they come from?
5. In short: Is a decision tree really useful in this situation, or is it just a way of camouflaging a wild guess, and making it look “rational?”

Discussion General Expectations

1. In your first posting, you should show a basic understanding of the issues involved in the module. In your second and subsequent postings, you should demonstrate a clear understanding of the material covered in the module.
2. Critically apply your understanding to the examples provided by others. Do those examples clearly illustrate the concepts being discussed? Why or why not?
3. Provide relevant sources for any information that isn’t common knowledge.
Rubrics