However, as writers, we are trained and practised in
the use of words. We create documents—reports, online
help, promotional materials—that are designed to be rhetorical
in the classical Aristotelian sense, that is “the faculty
of observing in any given case the available means of
persuasion” (1954/2001). In other words, we manipulate
words (our available means) to persuade readers/users that
our particular message is credible, meaningful, and useful
in a world flooded by a torrent of messages. Many of us,
however, are not trained and practiced in the use of images
for rhetorical purposes.
Do we understand sufficiently how visuals persuade readers/
users about messages? Unless we are also trained as artists or
art historians, how can we acquire this knowledge? The world of
still images and their analysis is vast. As O’Toole notes,