Vocabulary Tips: Is “Data” Singular or Plural?

In the grammarian community, there are some who will tip over a table and storm out of the room if anyone dares to combine the word “data” with a singular verb in their presence: e.g., “The data is conclusive: Many pedants have severe anger issues.”

Are these people overreacting? Yes, of course they are. But do they have a point regardless? Should we be using “data” as a plural noun? And, if so, what is the singular version?

Datum and Data

Traditionally, “data” was a plural. The singular form (i.e., the word for a single fact or piece of information) was “datum.” As such, we might say something like the following:

This datum is not significant in itself, but the combined data are hard to deny.

In this sentence, “datum” clearly refers to a single piece of information, with “data” reserved for a collection of facts. This is important when it comes to subject-verb agreement, so the singular “data” is paired with the singular verb “is,” while “data” is followed by the plural verb “are.”

Data as a Mass Noun

Over time, however, usage of “data” has changed. Thus, it is now commonly used as a mass noun (otherwise known as an uncountable or non-count noun).

This means that although “data” still refers to a collection of facts, it is treated as singular for grammatical purposes:

Information was collected from hundreds of respondents, so the data is very persuasive.

Consequently, “data” is now essentially a synonym for “information,” another mass noun that refers to a collection of facts or a large amount of evidence.

“Data is” or “Data are”?

Most of the time, even in academic writing, “data” is now used as a mass noun, so it should be combined with singular verbs. This would mean that “data is” is usually correct.

However, in some fields “data are” is still considered technically correct unless you’re referring to a single fact, in which case “datum” should be used instead.

As such, it’s a good idea to check your school’s style guide on this issue. If it doesn’t provide specific instructions, the singular “data” is probably fine. But you could always check with your professor to see if he or she has a preference if you want to be absolutely sure!