  A common learning goal for modern physics instructors is for students to
recognize a difference between the experimental uncertainty of classical
physics and the fundamental uncertainty of quantum mechanics. Our studies
suggest this notoriously difficult task may be frustrated by the intuitively
realist perspectives of introductory students, and a lack of ontological
flexibility in their conceptions of light and matter. We have developed a
framework for understanding and characterizing student perspectives on the
physical interpretation of quantum mechanics, and demonstrate the differential
impact on student thinking of the myriad ways instructors approach interpretive
themes in their introductory courses. Like expert physicists, students
interpret quantum phenomena differently, and these interpretations are
significantly influenced by their overall stances on questions central to the
so-called measurement problem: Is the wave function physically real, or simply
a mathematical tool? Is the collapse of the wave function an ad hoc rule, or a
physical transition not described by any equation? Does an electron, being a
form of matter, exist as a localized particle at all times? These questions,
which are of personal and academic interest to our students, are largely only
superficially addressed in our introductory courses, often for fear of opening
a Pandora's Box of student questions, none of which have easy answers. We show
how a transformed modern physics curriculum (recently implemented at the
University of Colorado) may positively impact student perspectives on
indeterminacy and wave-particle duality, by making questions of classical and
quantum reality a central theme of our course, but also by making the beliefs
of our students, and not just those of scientists, an explicit topic of
discussion.
