Illustration and redundancy

That images could be a memory aid is all the more remarkable considering the type of graphic used in Randolph's test. The news stories concerned competing satellite TV systems, and the accompanying graphics were photos of the two satellite dishes. For purposes of argument, I'd like to call this kind of image an illustration.

Let's say the defining characteristic of an illustration is a straightforward relationship to the accompanying text, one in which both text and image work toward the same communication goal, the same meaning. Because of this closeness, you could rather easily substitute text for an illustration. Such text might require more space, it might not enliven a gray field on paper, but from a meaning standpoint text can do the job of an illustration.

When Jakob Nielsen mentions skimping on graphics and limiting fancier effects to when they can best contribute to a page's information, he seems to have this sort of supporting, illustrative role in mind.

Now, even if Randolph's results indicate illustrations have a positive impact on recall -- and thus a potential use-value -- there's a danger here. Because of the closeness of meanings, illustrations can seem redundant. That's not so much of a problem under Randolph's test conditions, where the images are read from a network or floppy disk. But what about at modem speed? Slow download times mean we are caught in a waiting situation no matter what we're shown. Will we be pleased to wait for something we've already known? That seems to threaten the aims of anyone who wants to keep a web audience.

You could say Randolph's images of satellite dishes were, well, boring. Even so, they seemed to aid retention of information. But if you consider the speed factor, it's hard not to speculate how other kinds of images -- more memorable, challenging, or evocative images -- might impact retention. We await further tests.