Multi-User Interaction Principles


  1. Realistic Tool Handling

    The physical operation of geometrical manipulations must correspond to comparable activities with physical artefacts. If properly designed, the applied input devices afford the respective usage through their shape and appearance. This approach does not only provide for intuitive usability but also mutual awareness in co-located collaborative work is increased as the flow of interaction with the system becomes comprehensible through observing the operators actions.

  2. Dedicated Devices

    Principle 1 yet implies specialized devices for various actions like pointing, grasping, turning, etc. For realizing the sensible distribution of subtasks among colleagues some functionalities like object manipulation must be accessible to all users in parallel while other functionality like group navigation can only be controlled by one user at a time. So, there are single shared devices while other are provided as multiple duplicates. Further differentiation of devices for distinct functionality like object manipulation, parameter adjustments or reference setting facilitates parallel execution of complementary subtasks by multiple users. This also reduces confusion about interaction states, as the devices afford dedicated activities.

  3. Tool Combinability

    Complex functionality like constrained object manipulation and scaling can be achieved through the combined operation of multiple devices. This reduces the amount of necessary input devices or input device modes and fosters mutual assistance.

  4. Provide Basic Functionality to all users in parallel

    Individual navigation, pointing and referencing must always be possible to all involved users. E.g., distinct hand tools must all allow for direct pointing.