System of symbols that encodes measurement results. These symbols characterize the object in terms of a particular feature. Measurement scales are classed according to the way in which the results of two measurements can be combined: nominal scale, ordinal scale, interval scale, quotient scale, absolute scale. Each successive type of measurement scale allows more operations than the previous one.

• Measurement

• Quotient scale
• Nominal scale
• Ordinal scale
• Interval scale