  We estimate the expected behavior of a quantum model of heat engine when we
have incomplete information about external macroscopic parameters, like
magnetic field controlling the intrinsic energy scales of the working medium.
We explicitly derive the prior probability distribution for these unknown
parameters, $a_i, (i=1,2)$. Based on a few simple assumptions, the prior is
found to be of the form $\Pi(a_i) \propto 1/a_i$. By calculating the expected
values of various physical quantities related to this engine, we find that the
expected behavior of the quantum model exhibits thermodynamic-like features.
This leads us to a surprising proposal that incomplete information quantified
as appropriate prior distribution can lead us to expect classical thermodynamic
behavior in quantum models.
