ABSTRACT
Measurement was defined in Chapter 1. One of the most influential twentieth-century statements of the classical approach to measurement was that of psycho-physicist S.S. Stevens, who proposed four scales or degrees of measurement: nominal, ordinal, interval and ratio measurement (1946, 1975). Nominal and ordinal measurement are non-metric; interval and ratio measurement are metric. These theoretical standards are translated in measurement standards in the physical world through organizations such as the United States National Bureau of Standards (NBS). The NBS provides state, county and local officials with technical and operational guides that set out measurement specifications, standard tolerances and model laws designed to support the physical measurement system (Hunter, 1980: 869). The primary standards are those of the International System of Units (SI units) and are seven: length (meter, m), mass (kilogram, kg); time (second, s); electric current (ampere, A); temperature (kelvin, k); luminous intensity (candela, cd); and amount of substance (mole, mol) (Zebrowski, 1979).
