Sticklers for proper grammar are fond of pointing out how frequently people misuse the word ‘data.’ A ‘datum’ is singular; data are plural. The Economist Style Guide (a companion on my desk) explains:
Data and media are plural. So are whereabouts. Teams that take the name of a town, country or university are plural, even when they look singular: England were bowled out for 56.
Law and order defies the rules of grammar and is singular.
While this may be technically accurate, it has always clashed with my intuition – and not only because those who supposedly use the term incorrectly far outnumber whose who follow grammarian cant.
The question for me is whether ‘data’ is more like cats or more like water. The cats are increasingly annoyed about all this talk of grammar, but they remain distinct, countable, independent entities. The water, by contrast, is salty, ever-present, and part of an amalgamated mass. I may have seen Ghost in the Shell a few too many times, but the data-water equivalency long since became firmly entrenched for me.