  Large optical surveys provide an unprecedented census of galaxies in the
local Universe, forming an invaluable framework into which more detailed
studies of objects can be placed. But how useful are optical surveys for
understanding the co-evolution of black holes and galaxies, given their limited
wavelength coverage, selection criteria, and depth? In this conference paper I
present work-in-progress comparing optical and mid-IR diagnostics of three
"unusual" low redshift populations (luminous Seyferts, dusty Balmer-strong AGN,
ULIRGs) with a set of ordinary star-forming galaxies from the SDSS. I address
the questions: How well do the mid-infrared and optical diagnostics of star
formation and AGN strength agree? To what extent do optical surveys allow us to
include extreme, dusty, morphologically disturbed galaxies in our "complete"
census of black hole-galaxy co-evolution?
