extrapolation

[ik-strap-uh-ley-shuh n] /ɪkˌstræp əˈleɪ ʃən/

noun

an act or instance of inferring an unknown from something that is known.

Statistics, Mathematics. the act or process of estimating the value of a variable or function outside the tabulated or observed range.

Origin

1870-75; extrapolat(e) + -(t)ion

Examples from the web for extrapolation

But his statistical extrapolation suggests that it would not be easy.
Instead, the report's centerpiece is an odd extrapolation of the supply-and-demand theory to college education.
The extrapolation process is much more useful in the long term than the plug and play process.
Four years and five billion dollars later, the extrapolation seems premature.
And simple extrapolation from their results to demands for across-the-board austerity isn't a wise approach.
Current estimates by government agencies for risks from low doses rely on extrapolation from higher doses.
Beware of exponential extrapolation in a finite world.
Whatever the limits of extrapolation from this magazine, this much is clear.
Some extrapolation based on sampling seems necessary here.
Even with chimps, it is a big extrapolation from them to us.

Word Origin and History for extrapolation

by 1867, from extra- + back half of interpolation; original sense was "insert intermediate terms in a mathematical series." Transferred sense of "drawing a conclusion about the future based on present tendencies" is from 1889. Cf. extrapolate.

extrapolation in Culture

extrapolation [(ik-strap-uh-lay-shuhn)]

A mathematical procedure designed to enable one to estimate unknown values of a parameter from known values. A common method of extrapolation is to look at data on a curve, then extend the curve into regions for which there is no data. Extrapolation is often used to predict the future.

extrapolation in Technology

mathematics, algorithm
A mathematical procedure which estimates values of a function for certain desired inputs given values for known inputs.
If the desired input is outside the range of the known values this is called extrapolation, if it is inside then it is called interpolation.
The method works by fitting a "curve" (i.e. a function) to two or more given points and then applying this function to the required input. Example uses are calculating trigonometric functions from tables and audio waveform sythesis.
The simplest form of interpolation is where a function, f(x), is estimated by drawing a straight line ("linear interpolation") between the nearest given points on either side of the required input value:
f(x) ~ f(x1) + (f(x2) - f(x1))(x-x1)/(x2 - x1)
There are many variations using more than two points or higher degree polynomial functions. The technique can also be extended to functions of more than one input.
(2007-06-29)