Decision Trees

Methods

This document is intended to provide an introduction to decision trees.

Structure

  • A square decision node indicates a decision point between alternative options.
  • A circular chance node shows a point where two or more alternative events for a patient are possible.
Decision Node
Chance Node
  • Pathways are mutually exclusive sequences of events and are the routes through the tree.
  • Probabilities show the likelihood of partiuclar event occurring at a chance node.

A Trip to the Beach

Decision Node
Chance Node
Beach
Home
x
1-x
x
1-x
Rain
No Rain
Rain
No Rain