> Both constructions are standard. The plural construction is more common in print, evidently because the house style of several publishers mandates it.
The most complete online version of it that Google knows about is at http://www-old.accademiadellacrusca.it/forum/htdocs/phpBB2/v... .
Some key points and quotes:
- data isn't an ordinary plural. "Ordinary plurals ... can be modified by cardinal numbers; ... no one, it seems, can tell you how many data."
- "To summarize, data has never been the plural of a count noun in English. It is used in two constructions - plural, with plural apparatus, and singular, as a mass noun, with singular apparatus. Both constructions are fully standard at any level of formality. The plural construction is more common. If you are an editor for a publisher whose house style insists on the plural construction only, take care to be consistent ..."
- "There have been more occurrences of datum in popular sources since [about the middle 1960s]. Perhaps the insistence of many editors that data is a plural has accelerated the tendency for datum to be used as a singular of data"
Languages change slowly over time. I find myself using plural data when I'm talking science and singular data when I'm talking about hard drives. Hadn't noticed until your post!
Strange isn't it?