Scales
•Ordinal signifies which option is better than
another but not by how much
–e.g. options ranked 1, 2, 3, 4 based on performance against
a criterion
•Interval signifies difference between two
options but not absolute magnitude
– e.g. 3 versus 6 equivalent to 23 versus 26
• Ratio measures both difference and
magnitude
– e.g. A score of 6 is 3x better than a score of 2