... The compromise hinges on the hair-splitting difference between the so-called count nouns and mass nouns . ... The trick now is to realize that data can be both a count noun and a mass noun. If you use it as a count noun, it is always plural, and you are using it in lieu of the word ?facts?; the literal translation of datum from the original Latin is that it is ?a thing given?, hence data is ?things given? ? ... So if data is correct as both a count noun and as a mass noun, which should you use? ...