A method for determining a correction for an apparatus used in a process of patterning substrates, the method including: obtaining a group structure associated with a processing history and/or similarity in fingerprint of to be processed substrates; obtaining metrology data associated with a plurality of groups within the group structure, wherein the metrology data is correlated between the groups; and determining the correction for a group out of the plurality of groups by applying a model to the metrology data, the model including at least a group-specific correction component and a common correction component.