Definition:Goodness of Fit
Definition
Goodness of fit is a term used in statistics to mean the closeness of agreement between a set of observations and a hypothetical model which has been suggested as a possible source of data.
In particular, it is used when considering the fit of a random variable with a given probability distribution, with its known expectation and variance, with a view to determining whether that distribution is appropriate
Goodness of fit in such circumstances is often measured by a quantity involving the squares of the differences between the observations and the theoretical values predicted by the proposed distribution.
Best Fit
Let $S$ be a set of observations.
Let the goodness of fit of a set of model be evaluated by means of a least squares criterion.
The model such that this quantity is minimised, the goodness of fit is said to be the best fit.
Also see
- Results about goodness of fit can be found here.
Sources
- 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): goodness of fit