Data is/are

["Geoff Hart (by way of \"Eric J. Ray\" <ejray -at- raycomm -dot- com>)" <ght -at- MTL -dot- FERIC -dot- CA>]

I guess it really has been three months since this topic last came
around, and perhaps it hasn't yet made it into the commonly available
dictionaries or style guides, so I guess it's time to tackle it
again. Sigh. <gdrlh>

Strictly speaking, "data" is the Latin plural for the singular form
"datum", and in that sense, there's absolutely no question that the
word must be treated as a plural. End of discussion. However, we're
speaking/writing English here, not Latin, and that means we have to
look at modern (not ancient) usage, and in modern usage, "data" can
legitimately be both singular and plural, depending on the author's
intent. How can that be? The plural is obvious: that's just honoring
the original Latin usage. The singular is equally obvious if you're
familiar with the English technique of ellipsis (leaving something
unsaid): Nobody would argue with "the [collection of] data is..." or
"the data[set, -base, -bank] is...", and that means that data can
clearly function as a singular term. There's also a common difference
in how North American and British English treat collective nouns:
"the team is" and "the team are", respectively (but by no means
universally). And you thought this was a simple question, huh?

Speaking as an editor, the only problem I grapple with is one of
consistency: it would be perfectly valid to mix and match "data is"
and "data are" in a single document, provided that the author uses
each phrase correctly to denote a single collection of data, or the
many data elements taken as individuals. Problem is, even if you're
scrupulously correct about the usage, the result will always look
inconsistent to your readers, and we already confuse the poor dears
enough as it is. In the end, it's your call how seriously you police
the usage. I tend to be fairly strict about it within documents, but
less strict between documents, since I figure it's the
within-document variations that stand out most. YMMV.
--Geoff Hart @8^{)}
geoff-h -at- mtl -dot- feric -dot- ca

Hart's corollary to Murphy's law: "Occasionally, things really do work right."