# Evaluation Topics: Human-System Control **Intention of Use:** *What does the designer want the user to choose from and for which purpose?* ![](https://1763729276-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LiPPFFn8713gkOyphHP%2F-LicvurDfuhdghE1qZhx%2F-Licy6Zbuk4Y13g_eqZk%2FD9SKDF9WwAASY51.jpg?alt=media\&token=bf7ef0f9-0fe9-48ca-affc-1b28cdd55975) \- In **human control** (selection, manipulation and travel) tasks, the user typically specifies not only *what* should be done, but also *how* it should be done, more or less directly controlling the action. \ \- In **system control** tasks, the user typically specifies only *what* should be done and leaves it up to the system to determine the details. The system control is considered to ben an explicit action in stead of an implicit action. ### Human Control: taxonomy or usability characteristics ### **1. Users and User Tasks** * navigation * locomotion * selection * manipulation * user tasks **2. User Interface Input Mechanisms** * tracking user location & orientation * speech recognition & natural language input * interface mechanisms in general * pointers\&clicks\&props, like magic wands, flying mice, space balls, real-world props. * data gloves & gestural recognition **3. Virtual Model** * system information * user representation & presentation * agent representation & behaviour * virtual surrounding & selling **4. User Interface Presentation Components** * visual feedback & graphical presentation * haptic feedback & force and tactile presentation * aural feedback & acoustic presentation * environmental feedback and other presentation. ### Human-System Control: taxonomy of input controllers ![A taxonomy of 3D menus (Dachselt & Hübner, 2007)](https://www.wired.com/wp-content/uploads/2015/04/11UaRjr97fGePBtuMFkbqpw-1.png) According to the extended placement options by Bowman et al. menus can be placed in the following ways: * world-referenced (most desktop VR menus). * object-referenced (e.g. combo box in). * head-referenced (e.g. look-at-menu). * body-referenced (e.g. TULIP). * device-referenced (e.g. tool menu of the responsive workbench. * PIP tool-palette. * fade-up menu. ### System Control System Control can be defined as the user task in which commands are issued to: * (1) request the system to perform a particular function * (2) change the mode of interaction * (3) change the system state. ##