This new Center for Immersive Arts looks interesting; looks like well-written and -researched articles about immersive art, pervasive games, that sort of thing. IIUC, it's info spun out of Laura E. Hall's work on an Immersipedia, a potentially-big document. E.g., the latest article is an interview with a Sondheim biographer who's specifically writing about Sondheim's puzzlehunts.
This interview got me thinking about the movie "The Last of Sheila," co-written by Sondheim, a mystery story that involves a puzzlehunt. (I'm not the only one who was thinking about that; Hall was inspired to write a post about the movie, focusing on the puzzlehunt's timeline) The interview points out that Sondheim had the sense to playtest his puzzlehunts. (A theater nerd, he referred to playtesting as "dress rehearsal".) The puzzlehunt Game Control guy in "The Last of Sheila," as near as I could tell, didn't playtest his game. His game's first challenge has an awful lot of red herrings; it felt like he could have narrowed things down a bit and still had plenty of challenge left. He seemed surprised at how tough the second challenge was. The first time I saw the movie, I assumed that Sondheim was a feckless amateur puzzlehunt-runner, and wouldn't have considered playtesting. But now… I wonder.
Maybe he didn't playtest because he was cruel. He might have liked the idea that his players were wandering around confused.
Maybe he didn't playtest because… well, for the same reason we, the audience for a heist movie, don't get to see all the planning work ahead of the heist: planning isn't cinematic; we'll have more suspense if we don't know what's coming.
Anyhow, cool stuff, check out the Center for Immersive Arts.