  Research suggests that students often have difficulty transferring their
learning from one context to another. We examine upper-level undergraduate and
graduate students' facility with questions about the interference pattern in
the double-slit experiment (DSE) with single photons and polarizers of various
orientations placed in front of one or both slits. Before answering these types
of questions, students had worked through a tutorial on the Mach-Zehnder
Interferometer (MZI) in which they learned about interference of single photons
when polarizers of various orientations are placed in the two paths of the MZI.
After working on the MZI tutorial, students were asked similar questions in the
isomorphic context of the DSE. We discuss the extent to which they were able to
transfer what they learned in the context of the MZI to analogous problems in
the isomorphic context of the DSE.
