  The significance of the quantum feature of entanglement between physical
systems is investigated in the context of quantum measurements. It is shown
that, while there are measurement couplings that leave the object and probe
systems non-entangled, no information transfer from object to probe can take
place unless there is there is at least some intermittent period where the two
systems are entangled. PACS numbers: 03.65.Ca; 03.65.Ta; 03.65.Wj; 03.65.Ud.
