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Equation 4 · Part 1 · Building a Deployment Safety System That Actually Holds

Symbol pi

π\pi
π\pi

What this part means

the base rate.

Its job in the formula

pi is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.

Where the article explains it

where TPR\mathrm{TPR} and FPR\mathrm{FPR} are the true- and false-positive rates and π\pi is the base rate.

The passage around this formula

where TPR\mathrm{TPR} and FPR\mathrm{FPR} are the true- and false-positive rates and π\pi is the base rate. Plugging in TPR\mathrm{TPR} = 0.98 , FPR\mathrm{FPR} = 0.01 and π\pi = 0.0005 gives a precision of roughly 4.7%: more than nineteen out of twenty flagged requests are false alarms, even though the classifier’s headline accuracy sounds close to perfect. This is not a defect specific…

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Learn the underlying idea

A variable is a named place for a value. Its letter is a local label: x can mean position in one formula and a data point in another.

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Sources cited in the article section

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