What are the advantages and disadvantages of decison trees?
The obvious value of a decision tree is to visualize the choices available to you, and the long-range effects tomorrow of making a decision today. The shortcomings are of two kinds: first, the tree is an over-simplification – there are many factors to a decision that do not show up; for instance, what elements are in your control (for example, expansion vs. reduction) and what elements are not (for example, the stock market or war). Also, there is a built-in Manichean fallacy – either this choice or that. This gives too much weight to decisions already in the company’s history, and not enough weight to innovation or creativity. Second, a tree is only a metaphor, and if someone extends the metaphor (“let’s go back to the root” or “ if this limb breaks,” etc.) you commit the fallacy of argument by analogy. There is a human tendency to give the decision tree more “truth” than it really has – it is merely a visualizing tool to keep track of a complex decision process, and as such suffers from stultified thinking.