And, while I don't have a comprehensive answer to offer — and rather think that it will depend on the context of the organization anyway — I would like to suggest that pushing this idea forward could (maybe should?) happen in both the physical domain and the digital domain. Or, heck, even a mix of both. (If you can't get people wandering through the building itself, could you funnel an A/V feed to some location outside the building? A little observer station next to the box office? People could take a peek and come and go as they please?)

I personally LOVE that kind of engagement… just like, as David suggests, wandering through a busy kitchen on the way into a restaurant can be a thrill.

The difference is that the accidental audience gets a moment of discovery (rather than a formal invitation), has an element of anonymity (because of the glass window or the generally “public” nature of the park) and has the freedom to move on whenever they feel like it.

Contrast that to an open rehearsal with an invited audience who is expected to stay for a specific duration of time and can easily assume that their decision to leave is being interpreted by the artists as a sign of boredom or disinterest. Totally different scenarios.

So… How could we create opportunities for a “casual theater discovery” (in addition to the “rehearsing in a park” idea)?

But working in the open air is different. Being the second circle in a table read would be a lot of fun, it's just a variation on going to a play reading as it is. And yes, I think those kind of events would draw more interest.

Theatre “members” (a self selecting group of dedicated theatre goers) would be very interested in a process based rehearsal like we watched on the Saturday night of the Devised Work Convening… and they (and I) would never ever want to watch a blocking rehearsal or an iterative fix-the-line-reading rehearsal.

They would also be interested in second circling some table work and dramaturgical and design presentations like Kate Foy mentioned.

I don't think any of them would watch an “open dojo”, but I've seen folks come back and sign up.

I think there's an analogy there worth exploring. We've rehearsed in parks before and people would be curious and ask questions later. Sometimes they've come to see the show just because of that.

I don't know that it's a matter of being fragile. But I really don't think there's any serious interest in watching open rehearsals.

Think about the extra features on a DVD. They're fast, sharp, efficient little documentaries. If there were a raw, unfiltered look at their “process,” say three hours in the middle of filming one day, you'd skip to the next feature. It's just not that interesting. And that's in the comfort of one's own home.

There's no harm in the open rehearsal, and yes, it might be worth seeing if the full open-door policy would work. On the other hand, if I go to a restaurant, I may be curious to see what they do, I love watching Iron Chef, but I don't want to taste my dish when it's half-baked. And I don't expect them to offer that.

We need to open the door to let them in the building, we need to give them reasons to come in and see what's going on, but we don't have to open every door in the joint…

Maybe just leaving the door open? Is it so fragile that leaving the door open would ruin a show?

I'm not a fan of Open Rehearsals or Audience Talkbacks. I am a big fan of keeping rehearsals open, or rehearsing in the open, and talking with audiences. But if we're to leave the door open, it has to stay open, not just at the properly appointed times.

Yes, the disconnect in that moment was a perfect illustration of the difference in cultures. They see these new methods of communicating, as amusements. We see them as vital ways of connecting with other artists, other audiences.

Why, one could even develop a virtual theatre company of people spread around the world…

I didn't watch the conference, but your note about them being amused about getting a question from “Twitter” struck a chord. I can't prove it, but it feels to me like the disconnect illustrated in that exchange is sort of a fundamental issue here. What amuses me is that it's sort of frustrating to be on this side of that disconnect, but I'd much rather be over here than over there.