The other day I was doing a VFR practice approach into Tracy, CA when
the controller told me "reporting canceling IFR this freq, or on ground
via land line...". I told him "uh, ok canceling IFR, I didn't believe I
was IFR" (because I hadn't asked for or received an IFR clearance).
The controller told me that any aircraft on an approach clearance is
IFR for the purposes of the approach. I guess even controllers can be
students?

-Robert