Words versus pictures
Well, you'd be wrong.
But you'd also be wrong if you think I'd choose pictures.
Instead, I'd advocate for re-framing the issue. (What can I say, every now and then my legal training comes through.) More and more business communications now feature diagrams and charts. This phenomenon started as a result of research that showed some people absorb information better through pictures than words. And the trend is likely to grow, as computer users become more accustomed to, and comfortable with, icons representing things. (Ten years ago, who would have guessed that a cartoon paper clip would come to graphically represent a means of getting help (or an annoyance, depending on your point of view)?)
But using diagrams and charts is not without its perils -- and I'm not just talking about charts and diagrams that are sloppy or misleading. The best way to illustrate my point (pardon the pun) is by way of example.
I was reviewing a document recently when I came upon a statement that was very vague. When I questioned the client about what was meant by the comment, the client pointed out that my question was answered in the (fairly complicated) diagram in the middle of the page. Naturally, I felt stupid because it seemed quite obvious once she said it. (Of course, making the reader feel stupid is something most writers -- including this client -- should generally try to avoid, so my embarrassment was short-lived.)
But, this episode demonstrated rather nicely an important point: don't assume that everyone will look at diagrams and charts. Though it's great to include diagrams and charts to aid those who absorb information better through pictures than words, you can't ignore the fact that some people have difficulty interpreting charts and diagrams and so they routinely ignore them. (Guess which group I fall into?)
So, if you're using charts and diagrams in a document as well text, important information and conclusions should be made in both the text and the chart. The bottom line is: don't think in terms of informing the reader using either words or pictures -- use both!