Data refers to information or facts usually collected as the result of experience, observation or experiment, or processes within a computer system, or premises. Data may consist of numbers, words, or images, particularly as measurements or observations of a set of variables. Data are often viewed as a lowest level of abstraction from which information and knowledge are derived.

Etymology

The word data ( , , or ) is the Latin plural of datum, neuter past participle of dare, "to give", hence "something given". The past participle of "to give" has been used for millennia, in the sense of a statement accepted at fn, Data). In discussions of problems in geometry, mathematics, engineering, and so on, the terms givens and data are used interchangeably. Such usage is the origin of data as a concept in computer science:dataare numbers, words, images, etc., accepted as they stand.

Usage in English

Weasel: date=April 2009 In English, the word datum is still used in the general sense of "something given". In cartography, geography, NMR and technical drawing it is often used to refer to a single specific reference datum from which distances to all other data are measured. Any measurement or result is a datum, but data point is more common, albeit tautological. Both datums (see usage in datum article) and the originally Latin plural data are used as the plural of datum in English, but data is more commonly treated as a mass noun and used in the singular, especially in day-to-day usage. For example, "This is all the data from the experiment". This usage is inconsistent with the rules of Latin grammar and traditional English,Fact: date=July 2008 which would instead suggest "These are all the data from the experiment".

Some British and UN academic, scientific and professional style guides request that authors treat data as a plural noun. Other international organizations, such as the Institute of Electrical and Electronics Engineers Computer Society, allow its usage as either a mass noun or plural based on author preference. The Air Force Flight Test Center, in its publication The Author's Guide to Writing Air Force Flight Test Center Technical Reports specifically states that the word data is always plural, never singular.

Data is now often treated as a singular mass noun in informal usage, but usage in scientific publications shows a divide between the United States and United Kingdom. In the United States the word data is sometimes used in the singular, though scientists and science writers more often maintain the traditional plural usage. Some major newspapers such as the New York Times use it alternately in the singular or plural. In the New York Times the phrases "the survey data are still being analyzed" and "the first year for which data is available" have appeared on the same day. In scientific writing data is often treated as a plural, as in These data do not support the conclusions, but many people now think of data as a singular mass entity like information and use the singular in general usage." British usage now widely accepts treating data as singular in standard English, including everyday newspaper usage at least in non-scientific use. UK scientific publishing still prefers treating it as a plural. Some UK university style guides recommend using data for both singular and plural use and some recommend treating it only as a singular in connection with computers.