Science and Experiments
When either randomness or uncertainty modeled by probability theory is attributed to such errors, they are "errors" in the sense in which that term is used in statistics; see errors and residuals in statistics.
Every time we repeat a measurement with a sensitive instrument, we obtain slightly different results. The common statistical model we use is that the error has two additive parts:
- systematic error which always occurs, with the same value, when we use the instrument in the same way and in the same case, and
- random error which may vary from observation to observation.
The systematic error is sometimes called statistical bias. It is controlled by very carefully standardized procedures. Part of the education in every science is how to use the standard instruments of the discipline.
The random error (or random variation) is due to factors which we cannot (or do not) control. It may be too expensive or we may be too ignorant of these factors to control them each time we measure. It may even be that whatever we are trying to measure is changing in time (see dynamic models), or is fundamentally probabilistic (as is the case in quantum mechanics -- see Measurement in quantum mechanics). Random error often occurs when instruments are pushed to their limits. For example, it is common for digital balances to exhibit random error in their least significant digit. Three measurements of a single object might read something like 0.9111g, 0.9110g, and 0.9112g.
Read more about this topic: Observational Error
Famous quotes containing the words science and, science and/or experiments:
“Science is feasible when the variables are few and can be enumerated; when their combinations are distinct and clear. We are tending toward the condition of science and aspiring to do it. The artist works out his own formulas; the interest of science lies in the art of making science.”
—Paul Valéry (1871–1945)
“Imagination could hardly do without metaphor, for imagination is, literally, the moving around in one’s mind of images, and such images tend commonly to be metaphoric. Creative minds, as we know, are rich in images and metaphors, and this is true in science and art alike. The difference between scientist and artist has little to do with the ways of the creative imagination; everything to do with the manner of demonstration and verification of what has been seen or imagined.”
—Robert A. Nisbet (b. 1913)
“The trouble with tea is that originally it was quite a good drink. So a group of the most eminent British scientists put their heads together, and made complicated biological experiments to find a way of spoiling it. To the eternal glory of British science their labour bore fruit.”
—George Mikes (b. 1912)