I got asked this question twice in the same week as I heard both the British presenter and Australian guest on the fab statistics podcast More or Less agree with my prefered form just as I was beginning to doubt myself on it. Like with IELTS Writing Part One conclusions, after having researched it a bit to find out, I have both a strong opinion and an open mind about this controversial question.
First of all, it cannot be denied that “data” comes from the plural of the word “datum”, meaning “data” was historically plural. Therefore if you are perhaps a computer engineer who still uses the word “datum”, then you maybe have my special permission to say or write “The data are” if you really must. However if for you, like for the rest of us, “datum” is basically a disappeared word, “data” is uncountable, making “The data is” the only sensible form.
Here are some other reasons why:
– Nobody says or writes “three data”, meaning it has become uncountable
– “Information” is uncountable in English, so it kind of makes sense for “data” to be too
– Like most uncountable nouns, you can add “a piece of” to make the countable expression “a piece of data”
– Like many uncountable nouns, there are countable equivalents if you really want to add a number or “a”, making the relationship between “The data is” and “The statistics/ figures/ numbers are” the same as that between the uncountable “My advice is” and “My recommendations are”
If you Google this question, you’ll find that Wall Street Journal and The Economist basically agree with me while the APA style guide is just as confident about it but in the opposite way.