Post-Processing

Any operation or set of operations performed on personal data, whether or not by automated means

Steps performed after a machine learning model has been run to adjust its output. This can include adjusting a model's outputs or using a holdout dataset — data not used in the training of the model — to create a function run on the model's predictions to improve fairness or meet business requirements.

Performed after training by accessing a holdout set that was not involved during the training of the model. If the algorithm can only treat the learned model as a black box without any ability to modify the training data or learning algorithm, then only post-processing can be used in which the labels assigned by the black-box model initially get reassigned based on a function during the post-processing phase.

Typically performed with the help of a holdout dataset (data not used in the training of the model). Here, the learned model is treated as a black box and its predictions are altered by a function during the post-processing phase. The function is deduced from the performance of the black box model on the holdout dataset.