Usability study of VUI consistent with GUI focusing on age-groups

We studied the usability of a Voice User Interface (VUI) that is consistent with a Graphical User Interface (GUI), and focused on its dependency with user age-groups. Usability tests were iteratively conducted on 245 Japanese subjects with age-groups from 20s to 60s using a prototype of an in-vehicle information application. Next we calculated and analyzed statistics of the usability tests. We discuss the differences in usability with respect to age-groups and how to handle them. We propose that it is necessary to make voice guidance straightforward and to devise a VUI consistent with a GUI (VGUI) in order to let users understand the system structure. Also we found that the default design of a VGUI should be as simple as possible so that elderly users, who may be slow to learn the new system structure, are able to easily learn it.