Optimized ID3 algorithm based on attribute importance and convex function

ID3 algorithm is the key algorithm of decision tree. For the shortcoming that ID3 algorithm tends to choose attribute which has many values, attribute importance was introduced to improve ID3 algorithm. Next, according to the character of information gain, the improved ID3 algorithm was simplified to reduce the complexity of computing information gain by the convex function. Through experiment testing, the optimized ID3 algorithm can spend much less time to construct the high accurate decision tree and this decision tree has less average leaves.