State transition diagrams are a visual formalism for representing all possible states for computational systems (and the rules for transition between such states). Originally devised in relation to finite state machines, a variety of automaton, they facilitate the modeling of problems as computational issues. By translating actions into finite sets of steps (or states) with a condition for the transition to the next step (or state), the simple tasks of everyday life can more easily be turned into complex algorithms that encourage people to think like computers and the contingencies of interaction transformed into an issue of interface design.