1、What is machine learning
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define
observation -》learning -》 skilldata -》ML -》 skill
skill = improve some performance measure
ML = improve some performance measure with experience computed from data
eg. stock data -》 ML -》 more investment gaindata -》ML -》 improve performance measure
some use scenarios
when human cannot program the system manually
when human cannot ‘define the solution‘ easily
when needing rapid decisions that humans cannot do
when needing to be user-oriented in a massive scaleKey Essence of Machine Learning
exists some ’underlying（mean潜在的） pattern‘ to be learned、
but no programmable（easy）definition
somehow there is data about the patternapplication of machine learning
Twitter 分析餐馆好不好
推荐电影 需要知晓用户对于一些电影的评价-
components problem
f: x -> y， x，y 为data的输入和输出，而机器学习是在模拟f，从数据集D（x，y），通过演算法A，算出一个假说g（hypothesis）
{(xn,yn)} from f -> ML -> g
D(training examples) -> A(learning program) -> g 约等于 f （final hypothesis）假说的集合 H （hypothesis set），g 属于 H
learning model = A and HD —A on H—>(g:x->y)
Machine Learning and Data Mining
机器学习和数据挖掘是密不可分的
机器学习是实现人工智能的一种方式
统计是实现机器学习的一种方法
provable 可证明的 assumptions 假设，假定
