Decision Trees help you find patterns in data using a flow chart like structure. The best type of data would be qualitative, categorical and numerical. Although Decision Trees work with all types of data, they work best with numerical data. They must be able to have values that are numbers or there should be a way to translate them into numbers. Decision Trees are heavily dependent on the type of data as well as the quantity. If the number of data points is more than 100, Decision Trees would be a good model.