August 27, 2011
Dictionaries give you two different meanings of “statistic.” One has it that a “statistic” is “a numerical fact or datum.” I think this is the most common meaning — the most common way the word is used. But more properly it means “a quantity that is computed from a sample.” Said another way, a statistic is an estimate of another number computed using probability theory. A numerical fact that isn’t an estimate is just a numerical fact. Thus, a count of the number of people in an audience isn’t a statistic. But if you estimate the number of people in an audience by counting just a portion of the audience, then you have a statistic in the more precise sense.
The word “statistics” (from which the singular is derived) has a surprising etymology. Here’s Word-Origins.com on how it arose:
Date of Origin 18th c.
The term statistics (18th c.) etymologically denotes the ‘science of the state’. It comes from statisticus ‘of state affairs’, a modern Latin coinage based on classical Latin status (source of English state). It was the 18th-century German political scientist Aschenwall who brought it (in German statistisch) into general usage, in the specific sense ‘of the collection and evaluation of data (particularly numerical data) relating to the study of the state and its functions and institutions’. By the 1830s it had broadened out into its modern general sense. English acquired the word from German.
Are statistics a good thing? Joe Posnanski, always a joy to read, has a terrific post, “Statistics and Stories,” on this question today.