... As “data” is a plural countable noun in Latin, many people take the view that it should be used in the same way in English. Thus it requires plural verb forms, pronouns and quantifiers, e.g.:
Many of those data have already been entered into the system.
When we have received the data we can start to analyse them.
There are very few data in the set.
This usage is practical for scientific or academic writing because it allows for the use of the singular “datum”.
However, it is increasingly common to use “data” as a singular uncountable noun, as follows:
Much of that data has already been entered into the system.
When we have received the data we can start to analyse it.
There is very little data in the set. ...
... In articles in The Economist, for example, data is and data are occur with roughly equal frequency, excluding cases in which data isn’t the head of the subject NP. But much (of the) data and little (of the) data occur 90 times, against 15 for few (of the) data or many (of the) data. (These figures exclude comments, explicit discussions of the plurality of the noun, and references to things like data centres, data sets and data points—the last being the way in which people nowadays most often refer to what used to be called a datum). And in these cases, too, insistence on treating data as a plural can lead to grammatical inconsistencies or semantic anomalies. My guess is that an editor’s interpolation is responsible for the number discrepancy here:
At the moment, says Anthony Tuzzolino of the University of Chicago, there is plenty of computer modelling going on of the distribution of space dust, but few data.
And in the following, the plural verb require suggests that the number-crunching applies to one datum at a time:
Repeated aerial surveys over the coming years will also give the researchers insight into how vegetation recovers from fires, how the beetles affect this process, how erosion and sedimentation affect the region’s water resources, and whether fire creates opportunities for new species to invade. So many data, of course, require a lot of number crunching. ...