Definition
Numerical data
Data made of numbers that represent counts or measurements, not labels.
What it means
Ask what the numbers mean. If they tell “how many” or “how much,” they are numerical data and numerical comparisons make sense. A number can still be only a label: bus 12 is not twice bus 6, so those route numbers are categorical labels rather than numerical data in this sense.
Remember it
Numbers that count or measure, not numbers that merely name.
Example
The numbers of books read by four children are 2, 5, 5, and 8. These are numerical data because the values count books, and differences such as 8 − 2 = 6 books are meaningful.
Watch for
Telephone numbers, player numbers, postcodes, and route numbers may contain digits but are usually labels, so arithmetic with them does not describe the thing labelled.
Common mix-up
A number-shaped label is not automatically numerical data; the number must represent a count or measurement.
Exact meaning
Numerical data are values recorded as numbers whose numerical size has meaning, usually because they count or measure something. Numerical data may be discrete or continuous.