From Ernie…“For a given set of data, the difference between “what it is” and “what a person wants it to be” is perceived by that person as “bad data”.
Who do students belong to? at what point in time? when does it count? what is the benefit of having students belong to you? what is the cost of having students belong to you?
Is it “quality of data” or “quality of our understanding of data”?
Data are not controversial – the controversy is over our different understandings of what the data mean.