“…[20,21], or a vieo clip showing the robot's capabilities [22,25], or live demonstration performed by a researcher [23,24]. Second, some studies involved a small number of participants [26,27,30,31], and those studies conducted with many older adults had some limitations because users attended a single live demonstration without direct interaction with a robot [23]. In some studies, the experiment was conducted with a "Wizard of Oz" methodology (experiment in which subjects interact with a system that they believe to be autonomous, but which is controlled by a hidden person) [28], or the robot was tele-operated by the user [32].…”