Learn in the textbookData Operations and Levels of Measurement
DefinitionA scale (尺度) (level of measurement (尺度水準)) is a type of data defined by what its values represent, and the scale decides whether calculations such as comparing sizes or taking an average are meaningful.
ExplanationThere are four levels: the nominal, ordinal, interval and ratio scales. In that order, each level adds one more property to the values, and the range of meaningful calculations grows with it.
Memory hookThe Japanese word 尺度 originally meant a ruler for measuring length, and different rulers can measure different things.