1. Concept, device, or procedure used in arranging, measuring, or quantifying events, objects, or phenomenon in any sequence. Scales may be broadly classified as (1) Category scale: Sequence of numbers or words which only serve to identify certain entities or observations and have no quantitative significance; for example, a numbered or named list, or numbers on the uniforms of the members of a team. Also called nominal scale or qualitative scale. (2) Interval scale: Sequence of numbers in a fixed order representing amount, interval, or numeric values; for example, a distance or temperature scale. Also called quantitative scale. (3) Sequence scale: Ranked entities or items with a uniform spacing but no quantitative significance; for example, hardness scale (Moh's scale), pH Scale, or Richter scale. Also called ordinal scale.