Symbol n
n is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.
Read this term in its guide →Published equation contexts
Why this formula appears here
, so getting a usably precise estimate — a relative error in the neighbourhood of 20 to 25 percent, comparable to observing on the order of twenty events — requires . trials in total. This is where the arithmetic becomes unforgiving in a way the mean-difference case never does. Detecting a fixed three-percentage-point difference between two average success rates takes roughly the same, bounded number of trials — on the order of a thousand — regardless of how good either system actually is, because that calculation is about the spread of a difference, not the rarity of an event. Bounding or estimating a rare catastrophic-failure rate is different in kind: the required…
Read the representative guide
Symbol k
k occurs above the fraction bar. The numerator is divided by the entire denominator below it.
Read this term in its guide →Symbol q_τ
q_τ occurs below the fraction bar. The quantity above the bar is divided by this expression; zero is excluded as a denominator.
Read this term in its guide →How to interpret it
With a fixed numerator, increasing a nonzero denominator reduces the fraction. Its accuracy depends on the assumptions and range of use described in the article.
Research cited beside this formula
Published contexts (1)
A symbol can carry a different meaning in another article. Each occurrence keeps its own guide and term definitions.
Equation 26 · Model Evaluation
Why Average Success Rate Hides the Failures That Matter Most
This equation gives an approximation: it relates the quantities while allowing an approximation.
, so getting a usably precise estimate — a relative error in the neighbourhood of 20 to 25 percent, comparable to observing on the order of twenty events — requires . trials in total. This is where the arithmetic becomes unforgiving in a way the mean-difference case never does. Detecting a fixed three-percentage-point difference between two average success rates takes roughly the same, bounded number of trials — on the order of a thousand — regardless of how good either system actually is, because that calculation is about the spread of a difference, not the rarity of an event. Bounding or estimating a rare catastrophic-failure rate is different in kind: the required…
Equation guide → · Article →