Changes

'''Correlation''' describes the relationship of two factors to one another (see [[cause and effect]]).. In common usage, it denotes an association of one variable with another in quite general terms; for example, one might say, "success is correlated with hard work". In mathematics, however, and in science and engineering, which make use of mathematical concepts, correlation is a technical term with a precise definition.

'''Correlation''' describes the relationship of two factors to one another (see [[cause and effect]]). In common usage, it denotes an association of one variable with another in quite general terms; for example, one might say, "success is correlated with hard work". In mathematics, however, and in science and engineering, which make use of mathematical concepts, correlation is a technical term with a precise definition.

Correlation must be distinguished from causation (see article on [[correlation is not causation]]). When one factor changes and another factor changes with it, there is usually a direct relationship between the two factors, observed as a correlation. Alternatively, both changed could be the result of changes in a third factor. For example, the prices of two unrelated goods might increase during a period of [[inflation]]; the two price rises are correlated with each other but neither has caused the other.

Correlation must be distinguished from causation (see article on [[correlation is not causation]]). When one factor changes and another factor changes with it, there is usually a direct relationship between the two factors, observed as a correlation. Alternatively, both changed could be the result of changes in a third factor. For example, the prices of two unrelated goods might increase during a period of [[inflation]]; the two price rises are correlated with each other but neither has caused the other.