Can anyone tell me which is correct?- since data is plural, I am in a disagreement over this:
The data is correct.
The data are correct.

To score points with your English teacher, the data ***are*** definitely correct. Plural every time. (And so are the media, but that's a different story.)

But when the construction is less clear, the plural sounds odd to my ears: "The data coming in from the field suggest that we are going broke." Correct, but losing in the court of public opinion.

So you can be right...or popular. (Story of my life....)

I can agree with the previous post, because I got burned by a not-very-nice-and-rather-vindictive professor on my Master's thesis examination committee on this. Data is plural; datum is singular.

To clarify the above I would write:

The data are correct.
The data show that the theory is correct.
The data were taken using a computer.
and so on.

Who was it who said, "I would rather be right than be president"? Me too. Data are, every time.

I believe we've discussed this before and come to the conclusion that data as a single entity (used as a synonym for information) is singular, but when one is talking about more than one bit of datum it's plural.

http://wordsmith.org/board/showflat.pl?Cat=&Board=words&Number=1955&page=&view=&sb=&vc=1

Bingley

A related one is "Agenda" I believe. Rather than say "the next item on the agenda is Point 2", is it more appropriate to say something like ..."the next agendum is Point 2."

stales

I choose my rearguard actions with care these days. Latinate plurals are not a ditch I'm prepared to die in any more. I've taken to using agenda instead of agendum, curriculums instead of curriculae, and data instead of datum rather than getting funny looks or having people tell me I've misspelled them.

You may now all curse me for my moral torpitude. [Hanging Head with Defiant Gleam in the Eye emoticon]

You may now all curse me for my moral torpitude

To paraphrase a truly nasty bit of jingoism: "my countryman! My countryman right or wrong, but always my countryman!" The preceding rant inspired not by patriotism (yrch!) but by a desire to obfuscate my own shockingly inconsistent stand on the issue under discussion. The only one of your listed examples I cling to is "data" as a plural, apart from very occasional flirtations with curriculae, as curriculums is just plain ugly to say.

Latinate plurals are not a ditch I'm prepared to die in

I completely agree with this; and would go a step further. I disagree with your emphatic answer, Bean, because whilst that may be technically correct for Latin we are discussing English - and the word agenda has now been naturalised into the native tongue. Words only gain meaning by usage within a given speech community - so for me at least, agenda is a word that stands in for something like a collective noun rendering "a packet of information", and I therefore react to punctilious Latin usage as pretentious dogma! [/rant]

Ah well, I only wish I'd had the guts to tell that to my aforementioned professor. This guy was out for blood, and that was only one of the nitpicky things which he kept commenting on. Plus it is possible - I'll look through a few papers and see - that in scientific journals the data-plural thing is still consistently used, although in popular speech it is not as common. There are plenty of other grammatical constructions in our papers which seem like garbage to anyone else reading them, but are the most efficient or most clear way to express a thought!

the most efficient or most clear way to express a thought!

I agree, Bean. It's just that we are then operating within a particular speech community that has its own terms and consensus on meaning, which may well be marginally or completely at odds with non-specialist understanding of the 'same' word. I think that's what generates most of the heat in popular language discussion: it's a collision of two speech communities.

My fickle fingers keep wanting to type 'speach' - I shall have to wear the bottoms of my trousers rolled...