dy and
preservation.

In fact, the military instructor has the whole world as his workshop.
His notebook should be as ready to receive some especially apt saying
by a new recruit as the more ponderous words uttered by the sages. And
it should contain, not less, comments on techniques and methods used
by other speakers and instructors, which were visibly unusually
effective.

Above all, the consistent use of obvious and stereotyped devices and
methods of presentation should be avoided. For the fact is that _no
one has yet discovered the one best way_. In our service thinking, we
tend to get into a rut, and to use none but the well-tried way. For
example, we overwork the twin principles of thought-surprise and
thought-concentration, and in the effort to produce dramatic effect,
we sometimes achieve only an anticlimax. Using the techniques of the
advertising world, the military instructor puts his exhibits behind a
screen, in order to buildup anticipation, and at the appropriate
moment he yanks the cover off. This is perfectly effective, in some
instances. But it becomes a _reductio ad absurdum_ when he is working
with only one chart, or a pair or so of objects. Let's say that he is
talking about one machine gun, and he has one chart highlighting its
characteristics. How much more impressive it would be if they were in
the open at the beginning and he were to start by saying: "Gentlemen,
I am talking about this one gun and what keeps it going. It is more
important that you see and know this gun from this moment than that
you be persuaded by what I am about to say!"

It is a very simple but inviolable rule that where there is an obvious
straining to produce an effect by the use of any training aid, then
the effect of the training aid is lost and the speaker is
proportionately enfeebled. A famous World War II commander said of all
operations: "It is the chaps, not the charts, that get the job done."

What needs to be kept in mind is the psychological object in their
use. The scientists tell us, and we can partly take their word for it,
that people learn about 75 percent of what they know through their
sight, 13 percent through their hearing, and 12 percent through their
other senses. But this is a relative and qualitative, rather than an
absolute, truth. It has to be so. Otherwise, book study, which employs
sight exclusively, would be the only efficient method of teaching, and
oral instruction, which depends primarily o