levels of data

• Interval data - measured in fixed units with equal distance between the points on the scale eg time in seconds.
• The most appropriate measure of average for interval data is the mean.
• Interval is the highest level of data.
• Ordinal data - data that is presented in ranked order eg places in a beauty contest but the values themselves have no meaning eg the person who comes first is not twice as beautiful as the person who comes 5th out of 10 competitors.
• Ordinal data may be subjective.
• Ordinal is the mid-level of data.
• The most appropriate measure of ordinal data is the median.
• Nominal data - data that can be grouped into categories eg favourite lessons with no logical order to them.
• The most appropriate measure of average for nominal data is the mode.
• Nominal data is the lowest level of data.