Note for Machine Learning - ML by Akshatha ms

Topics ( 11 )

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Outline  Why Machine Learning?  What is a well-dened learning problem?  An example: learning to play checkers  What questions should we ask about Machine Learning? 1 lecture slides for textbook Machine Learning, T. Mitchell, McGraw Hill, 1997

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Why Machine Learning  Recent progress in algorithms and theory  Growing ood of online data  Computational power is available  Budding industry Three niches for machine learning:  Data mining : using historical data to improve decisions { medical records ! medical knowledge  Software applications we can't program by hand { autonomous driving { speech recognition  Self customizing programs { Newsreader that learns user interests 2 lecture slides for textbook Machine Learning, T. Mitchell, McGraw Hill, 1997

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Typical Datamining Task Data: Patient103 time=1 Patient103 time=2 ... Patient103 time=n Age: 23 FirstPregnancy: no Anemia: no Diabetes: no PreviousPrematureBirth: no Ultrasound: ? Age: 23 FirstPregnancy: no Anemia: no Diabetes: YES PreviousPrematureBirth: no Ultrasound: abnormal Age: 23 FirstPregnancy: no Anemia: no Diabetes: no PreviousPrematureBirth: no Ultrasound: ? Elective C−Section: ? Emergency C−Section: ? ... Elective C−Section: no Emergency C−Section: ? ... Emergency C−Section: Yes Elective C−Section: no ... Given:  9714 patient records, each describing a pregnancy and birth  Each patient record contains 215 features Learn to predict:  Classes of future patients at high risk for Emergency Cesarean Section 3 lecture slides for textbook Machine Learning, T. Mitchell, McGraw Hill, 1997

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Datamining Result Data: Patient103 time=1 Patient103 time=2 ... Patient103 time=n Age: 23 FirstPregnancy: no Anemia: no Diabetes: no PreviousPrematureBirth: no Ultrasound: ? Age: 23 FirstPregnancy: no Anemia: no Diabetes: YES PreviousPrematureBirth: no Ultrasound: abnormal Age: 23 FirstPregnancy: no Anemia: no Diabetes: no PreviousPrematureBirth: no Ultrasound: ? Elective C−Section: ? Emergency C−Section: ? ... Elective C−Section: no Emergency C−Section: ? ... Emergency C−Section: Yes Elective C−Section: no ... One of 18 learned rules: If No previous vaginal delivery, and Abnormal 2nd Trimester Ultrasound, and Malpresentation at admission Then Probability of Emergency C-Section is 0.6 Over training data: 26/41 = .63, Over test data: 12/20 = .60 4 lecture slides for textbook Machine Learning, T. Mitchell, McGraw Hill, 1997