PPT Slide

What is a Decision Tree?

Sunburn at the beach ?

Sunburn at the beach

The Big Question

How about homogeneity?

How about ?

Information Theory to the Rescue!

Extend to Class Membership

Historic Note:

Now, extend to the branches

So Choose the Best Test

OOPS!

OOPS! - continued

Gain Ratio Criterion

What about continuous attributes?

Grouping Attributes

Ok, what now?

The halting problem

The Nonhalting Problem

Pruning

How do we decide what to prune?

How to predict error

Method 2

Pruning Example

Seeing the forest for the trees

FRAGMENETED SUBCONCEPTS

Trees to rules

Contingency Tables

Contingency Tables - continued

Class Rulesets

Rulesets - continued

The last steps

Bagging and Boosting

Boosting

Email: machado@dsg.harvard.edu