Occasionally I see the use of the word "data" in definitions. For instance, one definition of an exact sequence starts off by saying, "An exact sequence of abelian groups (or modules or vector spaces) is given by the data of two homomorphisms [...]" (Perrin, Algebraic Geometry).

I've heard this term used in class as well once. In these instances data of course does not refer to data as used in statistics, as in data from an experiment.

What is the purpose of using such a strange word in abstract mathematics? Has anyone noticed this word?

vectorsfor disease" or insisting that "my answer is technically moreinformativethen yours because it uses more characters, so therefore carries more information." – Anton Geraschenko Dec 26 '09 at 23:29