b. Describing the nature of the attribute under investigation, including how it was measured and its units of measurement.

It's not enough for students to display data and spit out numbers till the cows come home. They also need to know whether a distribution is categorical or numerical, how the data were collected (by counting or measuring), and what the units of the data are.

Generally, units are important in math. But numbers without units make no sense in statistics. Honestly, without units, their answers might as well be in Wingdings.