  The measurement problem in quantum mechanics originates in the inability of
the Schr\"odinger equation to predict definite outcomes of measurements. This
is due to the lack of objectivity of the eigenstates of the measuring
apparatus. Such objectivity can be achieved if a unified realist conceptual
framework can be formulated in terms of wave functions and operators acting on
them for both the quantum and classical domains. Such a framework was proposed
and an equation for the wave function (13, 14) smoothly interpolates between
the quantum and classical limits. The arguments leading to the equation are
clarified in this paper, and the theory is developed further. The measurement
problem in quantum mechanics is then briefly reviewed and re-examined from the
point of view of this theory, and it is shown how the classical limit of the
wave function of the measuring apparatus leads to a natural solution of the
problem of definite measurement outcomes without the need for either collapse
or pragmatic thermodynamic arguments. This is consistent with Bohr's emphasis
on the primacy of classical concepts and classical measuring devices. Possible
tests of the theory using low-dimensional systems such as quantum dots are
indicated.
