The watchclock is another kind of interaction design, one whose function corrals the user into a single, linear, constrained sort of behavior. The night watchman has a fundamental social constraint — the desire to not get fired from their job. This constraint allows the watchclock patrol system to work so effectively (some would say insidiously) as an interaction design instrument of control.
Fahey, Christopher. Graphpaper (2009). Articles>User Experience>Management>Interaction Design