1. A method comprising: receiving a first amount of measurement data associated with measurements of a first plurality of sites on a surface of a first semiconductor wafer with known variations of at least one process parameter, structure parameter, or both, wherein at least one of the first plurality of sites includes a device structure; determining an expected response model of each of the at least one known process parameters, structure parameters, or both; determining an input-output measurement model based at least in part on the first amount of measurement data; and training the input-output measurement model based on parameter values determined from the expected response model.