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 was interested to see how a pioneer lived on this side of the country. His life is in some respects more adventurous than that of his brother in the West; for he contends with winter as well as the wilderness, and there is a greater interval of time at least between him and the army which is to follow. Here immigration is a tide which may ebb when it has swept away the pines; there it is not a tide, but an inundation, and roads and other improvements come steadily rushing after.”
—Henry David Thoreau (1817–1862)
“Another armored animal—scale
lapping scale with spruce-cone regularity until they
form the uninterrupted central
tail-row!”
—Marianne Moore (1887–1972)