  We show that in a quantum measurement, the preferred basis is determined by
the interaction between the apparatus and the quantum system, instead of by the
environment. This interaction entangles three degrees of freedom, one system
degree of freedom we are interested in and preserved by the interaction, one
system degree of freedom that carries the change due to the interaction, and
the apparatus degree of freedom which is always ignored. Considering all three
degrees of freedom the composite state only has one decomposition, and this
guarantees that the apparatus would end up in the expected preferred basis of
our daily experiences. We also point out some problems with the
environment-induced super-selection (Einselection) solution to the preferred
basis problem, and clarifies a common misunderstanding of environmental
decoherence and the preferred basis problem.
