Machine learning definition

• Arthur Samuel (1959). Machine Learning: Field of study that gives computers the ability to learn without being explicitly (明确地) programmed. (在没有明确地设置下，使计算机具有学习能力的研究领域)
• Tom Michell (1998). Well-posed (适当的) Learning Problem: A computer program is said to learn from experience E with respect to some task T and some performance measure P, if its performance on T, as measured by P, improves with experience E. (一个适当的学习问题：计算机程序从经验E中学习，解决某一任务T，进行某一性能度量P，通过P测定在T上的表现因经验E而提高。)

Machine learing algorithms:

• Supervised learning

• Unsupervised learning

Others: Reinforcement learning, recommender systems.

Also talk about: Practical advice for applying learning algorithms.