The contribution of unresolved source populations to diffuse emission at all wavelengths can induce anisotropies on small angular scales. Several recent studies have focused on the potential for anisotropy analysis of the large-scale isotropic gamma-ray background (IGRB) to identify the origin of this emission and to constrain the properties of known and proposed gamma-ray source classes. I will present a novel approach to identifying the source classes contributing to diffuse emission by combining the energy dependence of the total anisotropy and the total intensity, and demonstrate how this technique can be used in a model-independent way to extract the energy spectra of the contributing populations directly from the data, without making a priori assumptions about the spectra of any contributors. While this approach is applicable for any diffuse background at any wavelength, I will focus on its potential for understanding the IGRB. I will also discuss the implications for various source populations of the recent Fermi LAT measurement of the angular power spectrum of the IGRB.