cousera机器学习基石第三周笔记 machine learning foundation week 3 note in cousera Learning With Different Data Label Learning with Different Protocol Learning with Different Input Space Summary

Types of Learning

Credit Approval Problem Revisited

More Binary Classification Problems

Multiclass Classification: Coin Recognition Problem

Regression: Patient Recovery Prediction Problem

Structured Learning: Sequence Tagging Problem

Learning With Different Data Label

Supervised: Coin Recognition Revisited

## Unsupervised: Coin Recognition without $y_n$

unsupervised multiclass classification $Leftrightarrow$‘Clustering’:a challenging but useful problem

Unsupervised: Learning without $y_n$

Semi-supervised:Coin Recognition with Some $y_n$

avoid expensive labeling

Reinforcement Learning

Learning with Different Protocol

Batch Learning

a very common protocol

Online: Spam Filter that ‘improves’

Active Learning: Learning by ‘Asking’

Learning with Different Input Space

Concrete Features

human intelligence

Raw Features

need human or machines to convert to concrete ones(feature engineering)

Abstract Features

again need feature conversion/extraction/construction

Summary

  • Learning with Different Output Space:classification,regression,structured
  • Learning with Different Data Label$y_n$:supervised,un/semi-supervised,reinforecement
  • Learning with Different Protocol:batch,online,active
  • Learning with Different Input Space:concrete,raw,abstract