Measurements expressed on a ratio
scale can have an actual zero.
Apart from this difference, ratio
scales have the same properties as interval
scales: the divisions between the points on the scale have
the same distance between them and numbers on the scale are
ranked according to size.
There are many examples of ratio
scale measurements: length, weight, temperature on the kelvin
scale, speed and counted values like numbers of people, exam
marks - a score of zero really does mean no marks!! And at
0 kelvin the lowest temperature possible, it's so cold that
all molecules have stopped moving.
