We don’t think of them this way, but a pager and a doorbell are very similar. Both allow one person to one-way signal to another that they want their attention. But the social context surrounding the two are different in a way that makes it so that they are used differently, and that the signals come with different expectations. In particular, a doorbell’s context is more constrained than a pager’s allowing the sender to learn more from each message. It’s a nice example of social context supplementing social technology to influence interpretation. Pager’s are a generalization of the doorbell.
