Categorical Data

  • particular class of the data
  • usually describe qualitative information, sometimes without numerical meaning
    • color, election preferences, gender, age, level of education, …
  • usually collected using enquetes and forms

Two basic classes of the categorical data:

  1. nominal data (factors)
    • pure qualitative information without numerical context
    • cannot be even ordered
    • examples: color, gender, …
  2. ordinal data (ordered factors)
    • information that cannot be purely quantified, but
    • may be ordered (in some way)
    • examples: age, education level