Clay Shirky (Himself! - unless it's an imposter) responds to yesterday's comment on "Situated Software"
I'd go further, in fact, and say that it's not just the size but the coherence of the group that matters. 30 people on a subway car and 30 people in a startup have very different characteristics. The people in the subway car have too little in common to treat them as anything other than an aggregation of atomized users, but the 30 person company (or church group or sports team or chess club or...) has all sorts of interesting characteristics, including an implicit identity and reputation system, that the designers of software for that group can avail themselves of, if they are willing to forgo scale, generality and completeness in favor of treating the _group_ as the user of the software, and working with that in mind.