Human Computer Interaction (HCI) is the study of interaction between people (users) and computers. A basic goal of HCI is to improve the interaction between users and computers by making computers more user-friendly and receptive to the user's needs. Specifically, a long term goal of HCI is to design systems that minimize the barrier between the human's cognitive model of what they want to accomplish and the computer's understanding of the user's task.

Tracking: one of the big challenges of the augmented reality is the synchronization between the real and virtual information. The tracking is the system which must follow the position and orientation of the head of the user, in order to draw the right part of the virtual world. Different methods exist with their advantages and disadvantages. Between these methods, the optical tracking seems to be the most promising and only needs passive markers in the environment. Different libraries exist for marker detection and position estimation. In VICI, we will use one of those optical libraries. By extension, the use of elements of the real world instead of artificial markers should be exploitable.

Visualization peripherals: Most of the projects in augmented reality force the user to wear a consequent equipment. The latest hardware improvements tend to create visualization devices which are between HMDs and handheld displays. These are small displays which could be clipped to glasses. This permits to offer the immersion of the HMDs with the comfort of handheld displays.
In the VICI Project, we concentrate our work on the common caracteristics of these displays and we will imit us to deported displays in general, which could be the HMD's displays, or handheld's displays.

Multimodal systems combine two or more input modalities - like voice, write, touch, gesture... - with a multimedia output. Thus, the multimodality has an important role in new application allowing the combination of several modalitites regarding the task and the user's preferences. One of the difficulty during the multimodal interfaces' conception is the fusion of different modalities (sequence, parallelism) which influence the usability and ergonomie of an application.
Observing the context permits to offer to the user, in each situation, the most adapted modalities. In the VICI Project, the user will be able to interact with voice and gesture for annotating, navigating and information research.

Access to a pertinent information regarding the needs of the user and it's profile has an important role in the VICI Project.
In traditional information systems, the user plays the main role; the research is in this case based on explicit request sent to several research tools (active research). This approach gives a big liberty to the user, but impose competence and availability's constraints. If the user has specific needs, it could be preferable to propose directly the interesting information (passive research). In this project, the data will come from dynamic sources (internet, news, database of an existing application). The information filtering will play a key role to decide which data is relevant at which moment for the user. The user's specificities will be saved in an user's profile. In this system, the information filtering can be seen as a personal assistant which knows the interest of the user.
A filtering system will be developed and integrated to the VICI Project to provide this filter to the user.