data mining decision tree

1. 信息增益，熵

2. ID3, C4.5, 基于信息增益的判定树构造 top-down divide-and-conquer algorithm, 每一步选择一个属性，使得信息增益最大。

3. mining association rules 挖掘关联规则 - AProri算法

coverage => support

accuracy => confidence

association rules are often used when attributes are binary - either present or absent - and most of the attribute values associated with a given instance are absent.