# Mean Squared Error

## 16.11.2020 | Standard Functions/Loss

### Contents/Index

@Mean Squared Error
Coefficient of Determination

The mean squared error (or MSE or mean squared deviation (MSD)) measures the mean of the squared error between two values. That is $$MSE = \frac{1}{n} \sum_{i = 1}^{n} (V_i - W_i)^2$$ for $W,V$ vectors.

Since we square, we have no negative values.