cross-validated residuals

Measure the model's predictive ability. Residuals are the portion of the response not explained by the model. Cross-validated residuals are used to calculate the PRESS statistic. In PLS, the cross-validated residuals are the differences between the actual responses and the cross-validated fitted values. The cross-validated residual value varies based on how many observations are omitted each time the model is recalculated during cross-validation.