Levels of measurement

• Nominal:

  • Data is in categories
  • Are individuals the same or different in terms of the measured variable?
  • E.g. grouping people in terms of their favourite football team (Chelsea, Man City, Leicester)
• Ordinal:

  • Data is put in rank order (e.g. ranking of teams: Chelsea. (1st) Man City (2nd) Leicester (3rd)
  • Difference between each item- not the same (e.g person may like Chelsea a lot more than Man City, may be a small difference  in how much someone likes Man City or Leicester
• Interval:

  • Data is measured using units of equal intervals (same interpretation throughout)
  • Example: 40-50 degrees, same temperature difference as 80-90 degrees