Editing Statistic (section)

==Properties==
===Observability===
Statisticians often contemplate a [[parameterized family]] of [[probability distribution]]s, any member of which could be the distribution of some measurable aspect of each member of a population, from which a sample is drawn randomly. For example, the parameter may be the average height of 25-year-old men in North America. The height of the members of a sample of 100 such men are measured; the average of those 100 numbers is a statistic. The average of the heights of all members of the population is not a statistic unless that has somehow also been ascertained (such as by measuring every member of the population). The average height that would be calculated using ''all'' of the individual heights of ''all'' 25-year-old North American men is a parameter, and not a statistic.

===Statistical properties===
Important potential properties of statistics include [[completeness (statistics)|completeness]], [[consistent estimator|consistency]], [[sufficiency (statistics)|sufficiency]], [[estimator bias|unbiased]]ness, [[minimum mean square error]], low [[variance]], [[Robust statistics|robustness]], and computational convenience.

===Information of a statistic===
Information of a statistic on model parameters can be defined in several ways. The most common is the [[Fisher information]], which is defined on the statistic model induced by the statistic. [[Kullback information]] measure can also be used.