suppose. Usually 'observation' is an epistemological change, typically of a human learning the result of a measurement. A measurement is one system acquiring information about another system, hence changing the state (wave function) of the measured system. The exact wording is very interpretation dependent, and hence are metaphysical differences, not scientific ones.
I think I am more familiar with "observation" and " measurement" being synonymous ** -so that no actual acquisition of knowledge is implied simply ,perhaps a change of state in one system being directly connected to a change of state in another system.
But my understanding of Quantum Theories is flimsy.
**and "measurement" perhaps being synonymous with "interaction".