A discrete variable records precise, countable quantities as integers. Its values cannot meaningfully include decimals, unlike continuous measurements. section 1.2.2
Distinguish discrete variables from nearby data categories:
- Treat discrete data as quantitative when it represents measurable counts such as passengers, population, customers, or demand quantity. section 1.2.2
- Separate discrete counts from continuous measurements, which can take decimal values such as height or product price. section 1.2.2
- Do not confuse countable quantitative values with nominal categories, which have no sequence, or ordinal categories, which have an order. section 1.2.2
Items purchased in a transaction
A transaction record containing 5, 6, 7, 8, or 9 items uses a discrete variable for item count; fractional item counts would not fit. section 1.2.2
Figure 1.2 The divisions and subdivisions of data
Use the data-classification diagram to locate discrete variables among quantitative, categorical, structured, and unstructured data. section 1.2.2
