Obtaining a measurement of the metrology target on the processed substrate using a patterning process, the measurement being obtained using measurement radiation; And deriving a parameter of interest of the patterning process from the measured value, wherein the parameter of interest is corrected by a stack difference parameter, wherein the stack difference parameter is between adjacent periodic structures of the target or the metrology target and the substrate. Representing an undesigned difference in physical configuration between other adjacent targets on the image.