A method for estimating the size of a population. The method is generally applied to living organisms, such as fish in a lake.
The simplest example proceeds as follows. A sample of n1 individuals is obtained from the population (for example, by catching fish in a net). Each of these individuals is now marked in some fashion (for example, by attaching a tag) and is returned to the population. Later, a second sample (of n2 individuals) is taken from the population. Suppose m of these individuals are tagged. The sample proportion of tagged individuals is m/n2, and the population proportion is n1/N, so that an estimate of the population size, N, is N̂, given by
This estimate is known as the Petersen estimator of the population size. An alternative that avoids the problem caused when m is zero is provided by the Chapman estimator:
- Hamas
- Hamblin’s axiom
- Hamel basis
- Hamilcar Barca (c.229)
- Hamilton, Alexander (1757–1804)
- Hamiltonian
- Hamiltonian cycle
- Hamiltonian graph
- Hamiltonian mechanics
- Hamilton, James, 3rd Marquis and 1st Duke of (1606–49)
- Hamilton, Sir William Rowan
- Hamilton, Sir William Rowan (1805–65)
- Hamilton, William (1788–1856)
- Hamilton, William Donald
- Hamilton, William Rowan (1805–65)
- hamlet
- hammada
- Hammarskjöld, Dag Hjalmar Agne Carl (1905–61)
- Hammel, Heidi B (1960– )
- hammer chart
- hammering
- hammer mill
- Hammersley, John Michael (1920–2004)
- Hammersley–Clifford theorem
- hammer source