  We consider the issue of validating the relationship between electric fields
and optical intensity as proposed by the classical theory of electromagnetism.
We describe an interference scenario in which this can be checked using only
intensity measurements and without any other information regarding the details
of the arrangement of the associated fields. We implement this experimentally
using a triple Michelson interferometer and the results strongly suggest that
the method validates the classical relationship between optical intensity and
the associated classical field.

Physics Education;Optics