When using words like Data and Criteria do you tend to use "is" or "are" as a present tense verb? Technically, I suppose we should be using "are" but I think that I usually use "is" without thinking about it.

I use "is" as well.

I believe that's an incorrect usage; perhaps I need to retrain myself.

I used the singular till a sociology professor returned one of my papers with every singular verb crossed out in red and changed to plural, and the comment "data is a plural noun." I've been using plural ever since.