Definition
Datum
A datum is one recorded observation or value within a data set.
Continue from this idea into connected AXIO math.
Datum = one dot of data; data set = the whole collection.
Boundary: An entire row can contain several data values, so a whole row is not always a single datum.
What it means
Zoom in on one entry in a data set. If a table records plant heights, “14.6 cm for plant C” is one datum. The number 14.6 alone is incomplete because you would not know what was measured, for which case, or in which unit.
Remember it
Datum = one dot of data; data set = the whole collection.
Example
The class-height data set includes 138 cm, 142 cm, and 145 cm. “142 cm for Noor” is one datum: one recorded height for one student.
Watch for
An entire row can contain several data values, so a whole row is not always a single datum.
Common mix-up
Datum is a formal singular word. In everyday English, people often use data as a mass noun for the whole body of information.
Exact meaning
A datum is one recorded observation, value, or item of information in a data set. In formal statistical use, datum is the singular form of data; the variable, case, and unit or category are needed to interpret it.