## 5 Methodological Approach to Field Trials
### Empowerment in and through Interaction  
As in the methodological approach, the issue of empowerment, linked to the interaction of older users with the CLARC geriatric assistant robot, was taken into account in the design through two aspects. The first one was the interaction design. As described above, the CLARC robot offers flexibility in the interaction modes in order to adapt to the user's needs (according to their abilities/disabilities or use characteristics) and/or their interaction preferences. Four different interaction modes were implemented in the CLARC robot--vocal, tactile, gestural, physical buttons--thus adapting to the needs and preferences of each user in an intuitive and accessible way [42]:  
* The vocal mode was implemented through a text-to-speech (TTS) system, where the robot was able to talk to the patients, explaining what to do, making questions, etc. and the patients were able to talk to the robot and their speech was recognized by an Automatic Speech Recognition (ASR) system. This interaction mode implemented was one of the most natural ones in the robot. However, it was the least preferred by the patients [5]. * The tactile mode was implementing through the use of a touch-screen tablet situated in the torso of the robot. The different CGA tests were implemented in the tablet with questions to be answered by the patients and cognitive tasks to be performed, as the task of writing their name, memorizing terms or calculating among others. * The gestural mode was implemented through the use of the touch-screen tablet, but also with the use of a video camera which detected the position of the patients in front. The video camera was able to detect, for instance, whether the patient was sitting, standing, walking, or even swaying too much and was in danger of falling. Figure 4: Iterative phases of robot evaluation and improvements. * The physical button was implemented through a device external to the robot: a remote control that integrates a tablet and big physical buttons to help the patients complete the CGA tests from a more comfortable position than approaching the robot to press his tablet on his torso. They could do it from further away, sitting and without forcing their posture. Indeed, the remote control was developed during Phase 2 (see Figure 1b), based on the observation (results of successive user tests in France and Spain) that many users had significant difficulties with voice or touch control. In addition, the CLARC robot communicates verbally by programming the instructions of the synthetic voice so as to mimic a human attitude of benevolence towards its interlocutor: the least directive possible, allowing the necessary time of comprehension on the part of the user. In this way, the hypothesis examined is that the CLARC assistance robot would manage to put at ease users unfamiliar with robotic technologies, and to reassure them. In addition to multimodality, the second aspect related to the empowerment of users in the interaction with the CLARC robot is the accessibility criterion. As previously discussed, age implies decreases in motor, visual, hearing, and/or cognitive abilities. The modes of interaction must therefore be natural, intuitive (aspect 1) but also accessible (aspect 2). The patients with hearing impairments, for instance, could not hear the robot's voice properly, but the multimodal interface allowed them to see the subtitles of everything the robots was speaking and moreover, the touchscreen in the robot's torso shows the task to do next or questions to answer next, so patients with hearing impairments could interact with the robots. Another example is that of patients with motor disabilities, e.g., patients with voice or hand tremors. The multimodality allowed them the use of the remote control with big and physical buttons to interact with. Moreover, the time to answer was extended according to the users' needs. Patients with visual impairments could use the voice to communicate with the robot.