This old proverb is so worn with use that many of us don't stop to consider its underlying proposition. Instructional illustrations help learners understand and remember information in ways that text and lecture simply cannot.
Instructional illustrations are a broad class.
Imagine all the words that are replaced by the boxes and their relative positions, sizes, and colors in this chart. There is sometimes a feeling that illustrations are somehow less demanding of students and therefore remedial to the primary instruction. Illustrations are not always less demanding on students. Illustrations can make many kinds of information easier to understand, as will be demonstrated in Part 1, but not necessarily for all learners. Illustrations may often require verbal commentary or explanation in order for students to take full advantage of their benefits.