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Equation 2 · Part 3 · What Claude's Capability Evaluations Actually Measure

Symbol a

p(t)=11+exp⁡(a+blog⁡t),p(t) = \frac{1}{1 + \exp\left(a + b \log t\right)},
aa

What this part means

a occurs below the fraction bar. The quantity above the bar is divided by this expression; zero is excluded as a denominator.

Its job in the formula

a occurs below the fraction bar. The quantity above the bar is divided by this expression; zero is excluded as a denominator.

The passage around this formula

The method is a curve fit, not a lookup table, and stating it plainly exposes the assumption it rests on. For a task of human-expert duration t , METR fits a logistic curve to the model’s observed success rate across many tasks of varying length: p(t)=11+exp⁡(a+blog⁡t)p(t) = \frac{1}{1 + \exp\left(a + b \log t\right)}. with b > 0 , so predicted success falls as…

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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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