← All parts of this equation

Equation 15 · Part 3 · Ten Ways an Agent Evaluation Can Mislead You Even When It's Working Correctly

fraction

p^±1.96p^(1−p^)n.\hat{p} \pm 1.96\sqrt{\frac{\hat{p}(1-\hat{p})}{n}}.
fraction

What this part means

Divide the expression above the line by the one below it.

Its job in the formula

The expression above the fraction bar is divided by the complete expression below it. The denominator must not be zero.

The passage around this formula

4. Insufficient trial counts producing false confidence. A success rate reported from a small number of trials carries a much wider margin of error than the single reported number suggests, and the interval widens fast as the trial count shrinks. For a naive binomial estimate — treating each trial as an independent coin flip with unknown success probability p — the 95 percent confidence interval around an observed rate p^\hat{p} from n trials is approximately p^±1.96p^(1−p^)n\hat{p} \pm 1.96\sqrt{\frac{\hat{p}(1-\hat{p})}{n}}. At ten trials and an observed 90 percent success rate, that formula gives an interval of roughly plus or minus nineteen percentage points — an agent genuinely succeeding anywhere from about 71 percent to essentially…

Read this part in the article →

Learn the underlying idea

A fraction a/b means a divided by b. The top number is the numerator; the bottom number is the denominator, and it cannot be zero.

Open the illustrated fractions: division written vertically guide →

Sources cited in the surrounding passage

These citations provide research context; check each source for the exact claim it supports.