1. A computer-implemented method for designing test gauges for calibrating a simulation model of an optical lithographic process, the method comprising: identifying a first parameter of the simulation model; computing one or more of a width and a spacing of features in a pattern that optimizes a metric associated with the parameter; and designing one or more test gauges that include the pattern, wherein the identified parameter is chosen as an axis in building a model parametric space within a sensitivity space from which a target number of test gauges are selected; wherein the identifying and computing steps are performed using a computer.