Data: singular or plural?

Is data singular or plural? Do you use a singular or plural verb after data?

The answer can be quite tricky.

Some treat "data" as a mass noun, such as "sugar", "snow" or "dust", and insist on using singular verbs with "data".

A perfect example of this approach is the position of David Marsh, the Guardian style guru. Marsh claims the following:

It's like agenda, a Latin plural that is now almost universally used as a singular. Technically the singular is datum/agendum, but we feel it sounds increasingly hyper-correct, old-fashioned and pompous to say "the data are".

However, in IT publications, data should still be plural and take a plural verb after it.

To prove it, let us first search for "data is" and "data are" in Google Scholar

So, as you can see, "data is" is less frequent with the research publications as compared to "data are".

As the next step, let us refer to dictionaries.

As we can see, dictionaries say that, with the research publications, writers are supposed to use data as plural, whereas in non-scientific texts, data can be treated as singular.

As the final step, let us resort to the IEEE Editorial Style Manual for Authors.

Since IEEE is the principal standard with engineering publications, data should be always used as plural.

To conclude, the IT writers have to treat data as plural and use plural verbs with it according to the frequency statistics, dictionary guidance, and IEEE requirements.