  Stellar models provide a vital basis for many aspects of astronomy and
astrophysics. Recent advances in observational astronomy -- through
asteroseismology, precision photometry, high-resolution spectroscopy, and
large-scale surveys -- are placing stellar models under greater quantitative
scrutiny than ever. The model limitations are being exposed and the next
generation of stellar models is needed as soon as possible. The current
uncertainties in the models propagate to the later phases of stellar evolution,
hindering our understanding of stellar populations and chemical evolution. Here
we give a brief overview of the evolution, importance, and substantial
uncertainties of core helium burning stars in particular and then briefly
discuss a range of methods, both theoretical and observational, that we are
using to advance the modelling.
