Despite this inherent order, these categories are not scaled at equal intervals. In
contrast to ordinal data, data on a ratio scale are continuous (e.g., running time is
measured in minutes and seconds), ordered (one minute running is less than two
minutes running), and—unlike ordinal measurements—scaled at equal intervals (the
difference between one and two minutes is the same as between 11 and 12 minutes).
Additionally, ratios of two values from a ratio scale dataset are meaningful whereas
those from ordinal scales are not (e.g., five minutes of running is only half as much
as 10 minutes of running, whereas the category ‘slow-speed runners’ does not necessarily
represent a speed half as fast as the category of ‘medium-speed runners’).