Heuristics

1. Natural engagement.

Interaction should approach the user’s expectation of interaction in the real world as far as possible. Ideally, the user should be unaware that the reality is virtual. Interpreting this heuristic will depend on the naturalness requirement and the user’s sense of presence and engagement.

2. Compatibility with the user’s task and domain.

The VE and behaviour of objects should correspond as closely as possible to the user’s expectation of real world objects; their behaviour; and affordances for task action.

3. Natural expression of action.

The representation of the self/presence in the VE should allow the user to act and explore in a natural manner and not restrict normal physical actions. This design quality may be limited by the available devices. If haptic feedback is absent, natural expression inevitably suffers.

4. Close coordination of action and representation.

The representation of the self/presence and behaviour manifest in the VE should be faithful to the user’s actions. Response time between user movement and update of the VE display should be less than 200 ms to avoid motion sickness problems.

5. Realistic feedback.

The effect of the user’s actions on virtual world objects should be immediately visible and conform to the laws of physics and the user’s perceptual expectations.

6. Faithful viewpoints.

The visual representation of the virtual world should map to the user’s normal perception, and the viewpoint change by head movement should be rendered without delay.

7. Navigation and orientation support.

The users should always be able to find where they are in the VE and return to known, preset positions. Unnatural actions such as fly-through surfaces may help but these have to be judged in a trade-off with naturalness (see heuristics 1 and 2).

8. Clear entry and exit points. The means of entering and exiting from a virtual world should be clearly communicated.

9. Consistent departures.

When design compromises are used they should be consistent and clearly marked, e.g. cross-modal substitution and power actions for navigation.

10. Support for learning.

Active objects should be cued and if necessary explain themselves to promote learning of VEs.

11. Clear turn-taking.

Where system initiative is used it should be clearly signalled and conventions established for turn-taking.

12. Sense of presence.

The user’s perception of engagement and being in a ‘real’ world should be as natural as possible

Citations:

Alistair Sutcliffe, Brian Gault; Heuristic evaluation of virtual reality applications. Centre for HCI Design, School of Informatics, University of Manchester (2004).