synonym: standard error of calibration (SEC)
initialism: RMSEC
https://doi.org/10.1351/goldbook.10157
In calibration for \(N\) calibration data where \(c_{i}\) is an observed value and \(\hat c_{i}\) is the value predicted by the calibration function. \[E_{\rm{RMSEC}} = \sqrt \frac{\sum\limits_{i\,=\,1}^{i,=\,N} (\hat c_{i} - c_{i})^2}{N}\]
Note: Overfitting results in a small RMSEC, but poor predictive ability.