Design allows us to convey ideas. Ellen Lupton has it right when she says that "design is communication." There are times when you can visually support a concept or idea in such a way that it allows for a new depth of understanding.
I think I may have continued to study science in college had I not practically failed organic chemistry during my freshman year. Maybe I would be teaching a high school biology class right now if I had been able to "see" hydrogen and carbon like this: