- When numbers are assigned to characteristics for the purpose of data classification arbitrarily and without any regard to order.
- The numbers selected or assigned to a variable are arbitrary.
- Data endpoints are assigned these arbitrary numbers without any regard to order or rank.
- Females are assigned the number 1
- Males are assigned the number 2
- Being alive at the end of a study is assigned the number 1
- Being dead at the end of a study is assigned the number 2
- Gaddis ML et al. Introduction to biostatistics: part 1, basic concepts. Ann Emerg Med 1990;19:86-89.
Examples of Nominal Data