Capture-recapture methods were made in the wildlife biology to monitor the census of bird, fish, and inset populations. Recently, these methods have been utilized considerably in the areas of disease and event monitoring.
A lot of steps are taken in order to do the capture recapture method correctly. First you should select a group in which you are doing the capture recapture method then you must mark what ever it is that you catch and then release it, next you catch another group and market again after that you much capture some more and count how many there are unmarked and how many there are marked and that's how the process starts.
Capture-recapture methods have a long history, and they were first applied in the study of fish and wildlife populations before being adapted for other purposes. The use of these methods to the study of epidemiological problems came relatively late in this history and has been able to draw on advances in the other areas as well as in statistical methods more broadly. The simplest capture-recapture model is the so-called two-sample model, used solely to estimate the unknown size of a population.
The first sample provides the individuals for marking or tagging and is returned to the population, while the second sample provides the recaptures. Using the numbers of individuals caught in both samples (the recaptures) and the numbers caught in just one sample, it is possible to estimate the number not caught in either sample providing an estimate of the total population size. The guess required for this estimate to be valid can be spelt out in a number of ways.
However the key ingredients are, There is no change to the population during the investigation (the population is closed).There is no loss of tags (individuals can be matched from capture to recapture). For each sample, each individual has the same chance of being in the sample. The two samples are independent. Assumption really...