【AI】ML Basic Knowledge

 

Common Metrics

Name Explanation Key Params Usage Example
ROC Curve1 Receiver operating characteristic curve: A graph showing the performance of aclassification model at all classification threshhold. y: True Positive Ratex: False Positive Rate ROC curve is used to indicate the ROC Curve showing TP Rate vs. FP Rate at different classification thresholds.
AUC Curve2 Area under the ROC curve: One way of interpreting AUC is as the probability that the model ranks a random positive example more highly than a random negative example.when randomly choose one sample, the probability that the score of predicted true label comes before false label.   Positive and negative examples ranked in ascending order of logistic regression scoreAUC represents the probability that a random positive (green) example is positioned to the right of a random negative (red) example.1 AUC (Area under the ROC Curve).
TPR True positive rate, synonym for recall, actual positive data is classified as positive. $\frac{TP}{TP+FN}$    
FPR False positive rate, negative data is classified as positive. $\frac{FP}{FP+TN}$    

Concepts

Prediction and Recall

This is very well introduced in this article: Precision and recall.

In pattern recognition, information retrieval and classification (machine learning) “Classification (machine learning)”), precision and recall are performance metrics that apply to data retrieved from a collection, corpus or sample space.

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The difference between precision and recall is that precision measures how accurate of a certain retrieval, which differs a lot when retrieving multiple times from database. On the other hand, recall measures how complete of a certain retrieval.