Data is plural, or is it?
Whenever I attend a scientific talk, or read scientific publications, there is a significant chance that somebody forgets about the fact that data is the plural of datum. Hence, strictly speaking, it is wrong to say
This data shows that…
Instead, you should say
These data show that…
Because the mistake is so common, some people even argue that regarding data as singular is actually acceptable, see the discussion here . The use as a singular is also mentioned in Oxford English, but apparently does not apply to technical English. However, the journal editors I work with do not agree with that, and insist that data is plural.
Regardless of whether you consider data as a singular or plural noun, you should never use the word datas because it does not exist in English.