  The relations between observable stellar parameters are usually assumed to be
deterministic. That is, given an infinitely precise measurement of independent
variable, `$x$', and some model, the value of dependent variable, `$y$' can be
known exactly. In practise this assumption is rarely valid and intrinsic
stochasticity means that two stars with exactly the same `$x$', will have
slightly different `$y$'s. The relation between short-timescale brightness
fluctuations (flicker) of stars and both surface gravity and stellar density
are two such stochastic relations that have, until now, been treated as
deterministic ones. We recalibrate these relations in a probabilistic
framework, using Hierarchical Bayesian Modelling (HBM) to constrain the
intrinsic scatter in the relations. We find evidence for additional scatter in
the relationships, that cannot be accounted for by the observational
uncertainties alone. The scatter in surface gravity and stellar density does
not depend on flicker, suggesting that using flicker as a proxy for $\log g$
and $\rho_\star$ is equally valid for dwarf and giant stars, despite the fact
that the observational uncertainties tend to be larger for dwarfs.
