Social Interface Engineering

Interesting article from Joel On Software that points out that

Software in the 1980s, when usability was "invented," was all about computer-human interaction. A lot of software still is. But the Internet brings us a new kind of software: software that's about human-human interaction.

Discussion groups. Social networking. Online classifieds. Oh, and, uh, email. It's all software that mediates between people, not between the human and the computer.

For years I've taken the utilitarian tack and said that "If it ain't useful, who cares if it's usable?".  Spolsky takes this a bit further and points out that the social interaction that effective social  software supports has *got* to be right, carefully designed by looking at human behavior.  And more importantly, technology that models human-to-human behavior correctly doesn't need to be usable per se -- look at the explosion of text messaging.

http://www.joelonsoftware.com/articles/NotJustUsability.html