  No consensus seems to exist as to what constitutes a measurement which is
still considered somewhat mysterious in many respects in quantum mechanics. At
successive stages mathematical theory of measure, metrology and measurement
theory tried to systematize this field but significant questions remain open
about the nature of measurement, about the characterization of the observer,
about the reliability of measurement processes etc. The present paper attempts
to talk about these questions through the information science. We start from
the idea, rather common and intuitive, that the measurement process basically
acquires information. Next we expand this idea through four formal definitions
and infer some corollaries regarding the measurement process from those
definitions. Relativity emerges as the basic property of measurement from the
present logical framework and this rather surprising result collides with the
feeling of physicists who take measurement as a myth. In the closing this paper
shows how the measurement relativity wholly consists with some effects
calculated in QM and in Einstein's theory.
