Editing Mark and recapture (section)

=== Sample calculation ===
The example (n, K, k) = (10, 15, 5) gives
:<math>\hat{N}_C = \frac{(n+1)(K+1)}{k+1} -1= \frac{11\times 16}{6}-1 = 28.3</math>
Note that the answer provided by this equation must be truncated not rounded. Thus, the Chapman method estimates 28 turtles in the lake.

Surprisingly, Chapman's estimate was one conjecture from a range of possible estimators: "In practice, the whole number immediately less than (''K''+1)(''n''+1)/(''k''+1) or even ''Kn''/(''k''+1) will be the estimate. The above form is more convenient for mathematical purposes."<ref name="Chapman1951"/>(see footnote, page 144). Chapman also found the estimator could have considerable negative bias for small ''Kn''/''N'' <ref name="Chapman1951"/>(page 146), but was unconcerned because the estimated standard deviations were large for these cases.