Difference between revisions of "Correlation"
(proper incorporation of caution about correlation is not causation) |
(Example of air pollution) |
||
| Line 3: | Line 3: | ||
When one factor changes, and another factor changes along with it, there is usually a direct relationship. Alternatively, both could be caused by a third factor; for example, two prices of unrelated goods increasing during a period of [[inflation]] (see also [[correlation is not causation]]). | When one factor changes, and another factor changes along with it, there is usually a direct relationship. Alternatively, both could be caused by a third factor; for example, two prices of unrelated goods increasing during a period of [[inflation]] (see also [[correlation is not causation]]). | ||
| + | |||
| + | Once a correlation is established, scientists conduct research to determine causation. Are respiration deaths causing air pollution, or is it the other way around? It is easy to determine that sickness among the elderly does not cause air pollution. Rather, it is chemicals like sulfur dioxide (typically from coal burning [[power plant]]s) which are the culprit. | ||
==Links== | ==Links== | ||
Revision as of 13:42, January 3, 2009
Correlation refers to how a characteristic is common to a group, as in the correlation between hard work and success. Correlation is the mainstay of engineering and science. It is used to determine the relationships between factors (see cause and effect).
When one factor changes, and another factor changes along with it, there is usually a direct relationship. Alternatively, both could be caused by a third factor; for example, two prices of unrelated goods increasing during a period of inflation (see also correlation is not causation).
Once a correlation is established, scientists conduct research to determine causation. Are respiration deaths causing air pollution, or is it the other way around? It is easy to determine that sickness among the elderly does not cause air pollution. Rather, it is chemicals like sulfur dioxide (typically from coal burning power plants) which are the culprit.
