  We examine multiple techniques for extracting information from angle-resolved
photoemission spectroscopy (ARPES) data, and test them against simulated
spectral functions for electron-phonon coupling. We find that, in the
low-coupling regime, it is possible to extract self-energy and bare-band
parameters through a self-consistent Kramers-Kronig bare-band fitting routine.
We also show that the effective coupling parameters deduced from the
renormalization of quasiparticle mass, velocity, and spectral weight are
momentum dependent and, in general, distinct from the true microscopic
coupling; the latter is thus not readily accessible in the quasiparticle
dispersion revealed by ARPES.
