Pattern Classification an Diagnostic Decision

1. Pattern Classification an Diagnostic Decision Yongnan Ji

2. Outline • Introduction to Pattern Classification • Supervised Pattern Classification • Unsupervised Pattern Classification • Probabilistic models • Nueral Networks • Measures of Diagnostic Accuracy

3. Introducion

5. Nueral Networks

6. Measures of Diagnostic Accuracy True Positive Fraction (TPF) True Positive Fraction (TPF) False Negative Fraction (FNF) False Positive Fraction (FPF) With or without disease gold standard

7. Measures of Diagnostic Accuracy Positive Predictive Value (PPV) Negative Predictive Value (NPV)

8. Measures of Diagnostic Accuracy Weighted Cost Loss factor due to misclassification Total cost

9. Measures of Diagnostic Accuracy Decision variable z, for instance, body temperature difference with standard one (|T-T0|), to judge whther people have fever.

10. Measures of Diagnostic Accuracy Receiver Operating Characteristics (ROC) curve Used to evaluate the decision methods. The larger area under the curve, the better method the curve corresponds.

11. Measures of Diagnostic Accuracy