Schemas are a core concept that I have in all my psych classes--they are the key idea around which I create everything else (except biology). I use the Drew Appleby Demo on Déjà vu, not for that concept, but for the creation of a false memory based upon our schemas. The PPT I use is here:
Description of the activity I give I created for a textbook video lessons project and can be found on YouTube here: http://www.youtube.com/watch?v=rVEu3OVh3Uw&feature=related
The debriefing is here:
The demo has worked perfectly for the past 15+ years. Feel free to use and adapt.
For an assimilation example, I use "Monster's Inc." and the little girl "Boo" who calls Sully a "kitty." He's obviously a monster to us, but she does not yet have that in her schema, so she uses what she has available already--furry, with ears, four legs and a tail means "kitty." So far as I could tell, she never accommodated the idea of monster with Sully--she only had that with Randall. She distinguished the two.