4.2. Using models as interpretive tools

Large and uniform multi-wavelength and/or spectroscopic datasets are becoming increasingly common. An important consequence of this change in the nature of the data used to study galaxy evolution is that often the error budget is completely dominated by systematic and interpretive uncertainties. In this context, models of galaxy formation and evolution can help to understand and limit these systematic uncertainties through exhaustive analysis of realistic mock catalogs. A crude example of this kind of analysis is given in Section 3.1; a very nice example is the 2dFGRS group catalog of [Eke et al. (2004)]. Mock simulations of this kind of quality must become a more prominent part of our toolkit in order for the kind of interpretive difficulties faced in Section 3.1 or 3.3 to be successfully navigated.