Ted, I'm not sure I agree. While this exercise would be extremely valuable to screenwriters in learning what can be in an action line, there's plenty in a "tell" paragraph that can be recorded with camera and mic.
Consider this telling:
James looked at the party invitation again. It said "8:00 - 11:00." His watch read 11:30. He looked at the VCR's digital time. It matched his watch. He tapped his foot, then strode into the kitchen for a glass of water. James looked at the microwave clock, which read 11:31.
Couldn't all of that be shown and heard on film? And yet, it tells rather than shows, right?
Contrast with this showing:
James didn't need to pick up the party invitation to see "8:00 - 11:00" clearly, not after three previous double-checks. Maybe his watch was fast, with the new battery? He checked it against the VCR's digital time. 11:30 on both. Where could Emma be? Probably Jerry and Ann were carpooling the kids home, and Em was among the last, but still. Unable to stop his foot's impatient tapping, James strode into the kitchen for a glass of water he didn't want, the excuse for a peek at the microwave clock. 11:31.
As I see it, the difference isn't what can be seen and heard but the firm placement inside the POV character's head, including thoughts, feelings, and things he knows.
Maryn, disagreeing as pleasantly as possible