There is a veritable hotbed of controversy (among people who care about these sorts of things) (ahem, dorks) regarding whether the words data, criteria, and media should be treated as plural nouns or as mass nouns. (Mass nouns are nouns that cannot be made singular, yet they take a singular verb. Example: Milk is gross. For a refresher, click here.)
The old school method is to treat these nouns as normal plurals and use them with plural verbs. For grammar sticklers, this is the only correct way to use these nouns. Let’s first discuss the technically correct way to use data, criteria, and media, and then we’ll find out how these words function in the real world.
Data: facts, statistics, or other pieces of information
The singular form of data is the word datum. Traditionally, datum takes a singular verb, and data takes a plural verb. Here are some examples:
This datum is the most important piece of information in our research.
These data are inconclusive.
This datum shows little without the rest of the statistics.
The study’s data show us the big picture.
Criteria: a rule or principal used in evaluation
The singular form of criteria is criterion. Similarly, criterion takes a singular verb, and criteria takes a plural verb.
This specific criterion is too harsh.
As a whole, the criteria are fair.
The scandal is the criterion that seems to be deciding factor in her candidacy.
The criteria seem easy to meet, for most people.
Media: means of communication (radio, newspapers, television)
The singular form of media is medium. This means medium uses a singular verb, and media uses a plural verb.
The medium of the print newspaper is struggling.
People say the media are biased.
This medium, called the Internet, changes the way people get news.
Traditional media, such as print newspapers and magazines, change to fit modern needs.
How we use these nouns in the real world
You are much more likely to hear data, criteria, and media used with singular verbs, like in these examples:
The data shows us some interesting facts.
Their criteria is easy to fulfill.
The media gets a lot of blame.
This is because people tend to think of these words as mass nouns. For instance when a person is discussing the media, they are likely talking about all forms of media as one whole, as a career or as the group of people in that field. And when people refer to data, they often speak of several factors or statistics as a whole, not just one pinprick of information. So people are taking all the different sectors of media or all the individual pieces of data and speaking about them as if they were one entity: the media, the data, the criteria. Viola. Mass noun.
So, is one way more correct than the other? In my opinion, not really. I, of course, stick to the traditional method of using these nouns. I say “data are” and “media are” and “criteria are,” but I am more on the grammar stickler side. And I am swimming against the linguistic tide. The fact is that it is more common to hear these nouns being treated as mass nouns than the proper plural nouns they technically are. Grammar sticklers probably can’t stem the tide on this one, however.