Levels of measurement

• How many levels of measurement are there?

  Four
• What is nominal data?

  Data classified into distinct categories
• Can an item belong to multiple nominal categories?

  No, it can only belong to one
• What does ordinal data indicate?

  There is a specific order among categories
• Why is order important in ordinal data?

  It indicates ranking, not distance
• What is interval data?

  Data measured on a scale with equal intervals
• What distinguishes ratio data from interval data?

  Ratio data has an absolute zero
• What does having an absolute zero in ratio data allow?

  Making comparisons like "twice as big"
• How does the distance between points in ratio data compare to interval data?

  Distances are equivalent in ratio data
• If 2kg is half of 4kg, what type of data is this?

  Ratio data