Ok - let's look at the limitations of the different camera types for learning with.
I will assume that, for maximum learning potential, that even if a P&S, Compact or Bridge camera is suggested, it will (or should) be one that allows Manual, Aperture Priority, Shutter Priority and Program control, in addition to Auto.
the tiny sensor won't allow any useful experience of Depth of Field
the camera is unlikely to be able to be controlled manually, or even semi-automatically
limited focal length range (may even be digital zoom only)
P&S, Compact and Bridge:
the small sensor won't allow much useful experience of Depth of Field (DoF)
some may shoot RAW, allowing more PP experience to be gained
Interchangeable lens DSM or DSLR:
with a medium to shortish fast prime lens, to maximise DoF experience, plus
a standard kit lens to learn the disadvantages of average zooms and a range of focal lengths, plus
ideally/optionally a kit telephoto to give experience beyond 55 or 70mm
I sure hope Jeff remembers to come back and read all his replies!
If anyone needs an explanation of why I have said any of these things, just ask.