Recall and Precision

https://medium.com/@klintcho/explaining-precision-and-recall-c770eb9c69e9

TODO: draw own pictures, https://youtu.be/sarVw-iVWgc?list=PLiaHhY2iBX9ihLasvE8BKnS2Xg8AhY6iV&t=308
TODO: examples
TODO: examples of high/low recall and precision

Logistic regression

Logistic function

Metrics

Confusion matrix

Accuracy

Precision, Recall

AUC ROC

F_1

https://stackoverflow.com/questions/26355942/why-is-the-f-measure-a-harmonic-mean-and-not-an-arithmetic-mean-of-the-precision

If you want to know if your predictions are good, you need these two measures.
If one of these two values decreases dramatically, the f-score also does.

https://www.quora.com/What-is-an-intuitive-explanation-of-F-score

When measuring how well you’re doing, it’s often useful to have a single number to describe your performance.

https://www.mikulskibartosz.name/f1-score-explained/

f_{1} score

f_{2} score

f_{0.5} score

Why harmonic mean:

The harmonic mean is the equivalent of the arithmetic mean for reciprocals of quantities that should be averaged by the arithmetic mean
Precision and the recall are “naturally” reciprocals because their numerator is the same and their denominators are different. Fractions are more sensible to average by arithmetic mean when they have the same denominator.

superlearn