What does the IMF really tell us about star formation?
  Obtaining accurate measurements of the initial mass function (IMF) is often
considered to be the key to understanding star formation, and a universal IMF
is often assumed to imply a universal star formation process. Here, we
illustrate that different modes of star formation can result in the same IMF,
and that, in order to truly understand star formation, a deeper understanding
of the primordial binary population is necessary. Detailed knowledge on the
binary fraction, mass ratio distribution, and other binary parameters, as a
function of mass, is a requirement for recovering the star formation process
from stellar population measurements.
