| Finally, I'd like to note that many if not all the above
| mentioned authors have done real physics research as well as
| physics teaching. Of course, they have done original PER work.
| So these people are no "arm-chair theorists". It is also
| worth remembering that the physics involved in the listed
| sources is mostly introductory physics.
|
As a point of comment that may merit some discussion, the above
statement may not be true in 20-30 years, as the "stars" of the PER
community will have gotten their Ph.D.'s in PER. Many physics
departments are now beginning to confer the physics Ph.D. for PER.