Nominal Scale

The level of measurement of a variable in mathematics and statistics is a classification that was proposed in order to describe the nature of information contained within numbers assigned to objects and, therefore, within the variable. The levels were proposed by Stanley Smith Stevens in his 1946 article On the theory of scales of measurement. According to Stevens' theory of scales, different mathematical operations on variables are possible, depending on the level at which a variable is measured.
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in research, a scale where the numbers act only as data labels (eg 0=male, 1=female or a social security number). The only analysis that can be performed is to observe how frequently each of the scale members occurs in the survey (see nominal scale).

See principal scale. 1/4/71

Voir échelle principale. Voir aussi échelle. 1/4/71

Echelle d'un globe réduit ou générateur, représentant la sphère ou l'ellipsoïde, définie par le rapport à leurs rayons respectifs. Aussi appelé "échelle nominale". Voir aussi échelle. 1/4/71

This is a categorical (i.e., quantative and not qualitative) scale of measurement where each value represents a specific category that the variable's values fall into (each category is "different" than the others but cannot be quantitatively compared to the others).
See also, Elementary Concepts.