Pattern 05 · During

Shared Mental Model

The interface keeps what the human believes about the system’s state in sync with what that state actually is, so human and machine can predict each other.

The mechanism

machine state → resync

  1. 01Machine stateMode, intent, next move
  2. 02ExternalizeDisplay, light, sound, motion cue
  3. 03Human beliefBelieved state, predicted move
  4. 04 · Key momentDetect driftBelief ≠ actual state
  5. 05ResyncCorrect, then confirm alignment

At 02: Show intent before motion: where the machine will go next, not only where it is now.

At 04: Drift is caught both ways: the machine also models what the human expects it to do.

On this page

Without / with the pattern

Without

Robot moves, then Human assumes, then Near miss

The human’s picture of the machine drifts from reality, and no one notices until something goes wrong.

With the pattern

Intent shown, then Human predicts, then Coordinated work

Each side can anticipate the other, so they share a workspace safely.

Sources

Showing the current state is not enough on its own, because a person working alongside a machine is always predicting its next move.3 Signal intent before the motion starts, so that prediction has something to work from.2 The sync runs both ways as well: a machine with no model of what the operator expects it to do cannot tell when that expectation has gone wrong.

  1. How in the World Did We Ever Get into That Mode? Mode Error and Awareness in Supervisory ControlNadine B. Sarter and David D. Woods · 1995Paper
  2. Ten Challenges for Making Automation a “Team Player” in Joint Human-Agent ActivityGary Klein, David D. Woods, Jeffrey M. Bradshaw, Robert R. Hoffman and Paul J. Feltovich · 2004Paper
  3. Toward a Theory of Situation Awareness in Dynamic SystemsMica R. Endsley · 1995Paper
  4. Shared Mental Models in Expert Team Decision MakingJanis A. Cannon-Bowers, Eduardo Salas and Sharolyn Converse · 1993Book