Decision trees everywhere

The algorithm that we're going to use for our first machine learning exercise is called a decision tree classifier. A decision tree is a set of rules that describe the process of decision making (see figure 2.5 for example).

Decision trees are widely used outside the machine learning in different domains; for example, in business analysis. The popularity of decision trees is understandable: they are easy to interpret, and nice to visualize. For many years, they were built manually using the domain expert knowledge. Fortunately, now we have machine learning algorithms that can easily turn almost any labeled dataset into a decision tree.