Surveillance

Roles: observer, subject, watching, monitoring, notification, visibility, detection

Systematic observation of subjects by watchers who track, record, and respond to changes. Unlike casual observation, surveillance implies sustained attention, asymmetric knowledge (the watcher knows more than the watched), and a protocol for acting on what is observed. This frame maps onto software event systems where components register interest in changes and receive notifications — the subject is watched, the observer watches, and the system ensures nothing escapes notice.

As Source Frame (1)

• The Observer Pattern → object-oriented-design