
Mean integrated squared error

In statistics, the mean integrated squared error (MISE) is used in density estimation. The MISE of an estimate of an unknown probability density is given by
where "ƒ" is the unknown density, "ƒ""n" is its estimate based on a sample of "n" independent and identically distributed random variables. 
Here, E denotes the expected value with respect to that sample.
The MISE is also known as "L"2 risk function.