Somehow I managed to post my reply to a different thread on Take 20!
Here is my response from yesterday:
I second the idea of promoting the idea in general RPG terms, this also gives you the option to use another system if PF doesn't work for your class.
I know Fate Accelerated has been used by teachers for example, and FAE is also much cheaper to purchase for a class ($5 per hard copy with a PDF that is pay-what-you-want including free!) and a much quicker read at less than 50 digest sized pages.
The key thing is to go into this with a goal in mind and how you will determine if you were successful, in the FAE example linked above the the goal was to "to get them [the students] thinking of characters and narrative, of using their imaginations and sharpening their improvisational skills".
So as well as playing I would suggest organising discussion groups after a scene or scenario to have students describe how they felt about the game, what they learned etc.