机器学习笔记(1): 基础概念

1. 机器学习基础概念

1.1 定义

A computer program is said to learn form experience E with respect to some task T and som performance measure P, if its performance on T, as measured by P,improves with experience E.
例如：根据你将那些邮件标记为垃圾邮件的行为，邮件程序学习更好的过滤邮件
T: Classifying emails as spam or not spam
E: Watching you label emails as spam or not spam
P: The number(or fraction) of emails correctly classfied as spam/not spam

1.2. 机器学习算法分类

1. 监督学习（Supervised learning）
2. 无监督学习（Unsupervised learning）
3. 其它：增强学习（Reinforcement learing）、推荐系统（recommender systems）