Interval Scale
The interval type allows for the degree of difference between items, but not the ratio between them. Examples include temperature with the Celsius scale, and date when measured from an arbitrary epoch (such as AD). Ratios are not allowed since 20°C cannot be said to be "twice as hot" as 10°C, nor can multiplication/division be carried out between any two dates directly. However, ratios of differences can be expressed; for example, one difference can be twice another. Interval type variables are sometimes also called "scaled variables", but the formal mathematical term is an affine space (in this case an affine line).
Read more about this topic: Numerical Data
Famous quotes containing the words interval and/or scale:
“[I have] been in love with one princess or another almost all my life, and I hope I shall go on so, till I die, being firmly persuaded, that if ever I do a mean action, it must be in some interval betwixt one passion and another.”
—Laurence Sterne (1713–1768)
“With a defeated joy,
With an auspicious, and a dropping eye,
With mirth in funeral, and with dirge in marriage,
In equal scale weighing delight and dole.”
—William Shakespeare (1564–1616)