Welcome to my world - the physics of writing about data

In a recent proposal, I had the need to refer to the word "data," and therefore had to decide whether the word "data" is singular or plural. In other words, should I say "data is bla bla bla" or "data are bla bla bla"? Neither - I shouldn't be using the phrase "bla bla bla" in a proposal.

Grammar Girl has pointed out one of the underlying issues that must be addressed to answer this question:

Count nouns are used for objects that can be counted; that is, they're distinct objects that can be numbered. For example, in my refrigerator there are eggs, apples, and lemons. These are all count nouns. Count nouns can be singular or plural, and when you use them as the subject of a sentence, the verb must correctly reflect that number, as in The last apple IS on the bottom shelf or The eggs ARE fresh.

Mass nouns, on the other hand, are used for things that don't have a natural boundary and can't be counted. Also in my fridge are butter, iced tea, and bacon. These are all mass nouns. Mass nouns always take a singular verb, as in The iced tea IS already sweetened and They say bacon IS bad for you, but I love it.*

In a sense, we're entering into the realm of physics here. Now we could take things too far and claim that one could count the number of molecules in a particular drop of water, but common sense should prevail here.

Based upon this distinction between mass and count nouns, we can now ask whether the word "data" is singular or plural. Grammar Girl gives us the definitive answer to this question:

[B]oth usages are standard.

Depending upon the circumstances, either of these sentences may be required:

Much of this data is useless because of its lack of specifics.

Many of these data are useless because of their lack of specifics.

This disconcerts those of us who want definitive answers to questions. Shouldn't grammar provide such definitive answers? Perhaps, but we're not dealing with grammar here, as Ian S. Fraser and Lynda M. Hodson note.

Each language has its own systematic ways through which words and sentences are assembled to convey meaning. This system is grammar. But within the general grammar of a language, certain alternative ways of speaking and writing acquire particular social status, and become the conventional usage habits of dialect groups.

Grammar is the list of possible ways to assemble sentences: usage is a smaller list of the socially preferred ways within a dialect.

So how do you determine usage? It's best to refer to some source document which consistently provides guidance. There are a variety of style and usage guides, including the Chicago Manual of Style and the Microsoft Manual of Style for Technical Publications.

And yes, Apple fanbois can turn to a PDF called the Apple Publications Style Guide. (I was unable to find the word "insanely" in that style guide, by the way.)

P.S. Be sure to read what Grammar Girl says about fish.