Graphic interfaces - Cognitive foundations

Graphical User Interfaces (GUIs) are the most widely used interfaces today. On the one hand, they involve visual representations on the screen of both the task objects the user is performing and the dialog objects that support the interaction, and on the other hand, a device for designating objects on the screen, which serves to initiate the interaction chain.

Paradoxically, the main characteristic of graphical user interfaces has less to do with their graphic appearance than with the interaction metaphor they use. All are based on the metaphor of "direct designation interaction", as opposed to the "conversation" metaphor that characterizes interfaces based on text-based command languages such as Shell Unix.

For many years, practically since the mid-1980s, all computers have been equipped with graphic displays. Even text is drawn on them, which means, for example, that any number of fonts can be used. The graphical aspect of an interface is therefore no longer a discriminating criterion. Even Unix's VI (pronounced "vihai") editor makes use of some of the possibilities offered by graphical screens. The real distinction lies in the way you interact with the machine.

With this in mind, in this first article we present the cognitive mechanisms on which interactions in graphical user interfaces are based, then in a second article [H 7 216] we describe the main interactors in graphical user interfaces, explaining the reasons for their organization and architecture. Finally, the last section [H 7 217] shows how these interfaces are implemented and the main associated development environments.