The analysis of events governed by probability is called statistics. In statistics, a group of facts is collected and classified in a methodical manner, which is why such a study is important to the fields of science, finance, social research, insurance, engineering, and sundry other areas. In general, the data are grouped according to their relative number, then certain other values are determined based on the characteristics of the group. The most important part of statistical theory is sampling. This is because in most applications, the statistician is not only interested in the characteristic of the sample, but also the characteristics of some much larger population. (For information about samples and populations, see below.)