Comparison of categorical and quantitative variables

A variable can be classified as one of the following types:
Categorical variables
Categorical variables are also called qualitative variables or attribute variables. The values of a categorical variable are mutually exclusive categories or groups. Categorical data may or may not have some logical order.
Quantitative variables
The values of a quantitative variable are numbers that usually represent a count or a measurement.

Often, you will collect both categorical data and quantitative data when exploring a single subject. Categorical variables are often used to group or subset the data in graphs or analyses. Here are some examples of categorical and quantitative data that you could collect when exploring the same subject:

Subject of the analysis Possible categorical variables Possible quantitative variables

Household appliance sales

Type of appliance; Make and model

Sale price

Automobile body painting

Paint flaws (peel, scratch, smudge, other); Paint colors

Temperature of metal to be painted; Thickness of paint layer

The following tables show examples of categorical and quantitative variables for different types of data:

Examples of categorical variables

Data type Examples

Numeric

  • Gender (1=Female, 2=Male)
  • Survey results (1=Agree, 2=Neutral, 3=Disagree)

Text

  • Payment method (Cash or Credit)
  • Machine settings (Low, Medium, High)
  • Product types (Wood, Plastic, Metal)

Date/time

  • Days of the week (Monday, Tuesday, Wednesday)
  • Months of the year (January, February, March)

Examples of quantitative variables

Data type Examples

Numeric

  • Number of customer complaints
  • Proportion of customers eligible for a rebate
  • Fill weight of a cereal box

Date/time

  • Date and time payment is received
  • Date and time of technical support incident