VISTA
is a multidisciplinary/cross-sectoral project aimed at developing
a 'virtual assistant' embodying a speech based interface between
digital television viewers and the content and functions of an
electronic programme guide (EPG). While it is anticipated that
the resulting interface will make EPG access easier for all, the
main target groups are visually impaired (VI) and older viewers
who experience disproportionate difficulty using currently popular
GUI style EPGs.
Despite
their great potential for improved usability, speech interfaces
are unlikely to prove the 'universal panacea' some anticipate.
Rather they raise a host of new human factors issues. For example,
current technology disallows a truly 'conversational' interface,
thus a structured dialogue is required which raises issues about
keeping users 'on-script' (e.g. prompts and other additional support)
and providing efficient routes to the information users require.
Many of the VI population are elderly and thus also have hearing
problems which emphasizes the intelligibility of the synthetic
speech output. Qualitative results are presented from iterative
evaluations involving (non-VI) elderly users and a wide age range
of VI users of a PC based prototype designed to be compatible
with digital broadcast technology.
