Different types of attributes in a data mining data set are:

1. Nominal:

   • The values of a nominal attribute are just different names, i.e. nominal attributes provide only enough information to distinguish one object from another(=,≠)

   • Examples: zip codes, employees ID numbers.

2. Ordinal:

   • The values of an ordinal attribute provide enough information to order objects(<, >)

   • Examples: Hardness of minerals, street numbers

3. Interval:

   • For interval attributes, the differences between values are meaningful,i.e. a unit of measurement exists(+,-)

   • Examples: Calendar dates, Temperature in Celsius or Fahrenheit.

4. Ratio:

   • For ration variables, both differences and ratios are meaningful(*,/)
   • Examples: Temperature in Kelvin, counts, age.