1. A method of selecting a subset of test patterns from an initial set of test patterns, the initial set of test patterns having a larger number of test patterns than the number of test patterns in the subset, the method comprising: generating an information matrix for the initial set of test patterns, wherein the information matrix comprises an input value for each of a plurality of parameters for variable terms of a computational lithography model that models at least part of a process involving lithography, the input values determined for each of the test patterns in the initial set of test patterns; and selecting, by a computer hardware system and based on the information matrix input values of the plurality of parameters determined for each of the initial set of test patterns, the subset of test patterns for calibrating the computational lithography model.